Mitsubishi Outlander: DTC B1206, B1207, B1B00, B1B01, B1B02, B1B03, B1B04, B1B05, B1B06, B1B07

DTC B1206: Passenger's Air Bag OFF Indicator Light (Open Circuit)

Air Bag OFF Indicator Light Drive Circuit

CAUTION If DTC B1206 is set in the SRS-ECU, always diagnose the CAN main bus line.

CIRCUIT OPERATION

• Power for the passenger's air bag OFF indicator light is supplied from the fusible link (34).
• The passenger's air bag OFF indicator light illuminates when the ignition switch is turned to the "ON" position and goes out after approximately seven seconds if there is not a malfunction in the SRS system. In the following situations, the indicator will stay on to show that the passenger's (front) air bag is not operational.
• The occupant is determined to be less than 66 lbs (30 kg) by the occupant classification- ECU.
• The front passenger's seat is not occupied.

DTC SET CONDITIONS

This DTC will be set if an open circuit has occurred in the wiring harness between the passenger's air bag OFF indicator light and the SRS-ECU.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors
• Malfunction of the SRS-ECU
• Malfunction of the passenger's air bag OFF indicator light

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4.  Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check the passenger's air bag OFF indicator light.

1. It is checked whether the passenger's air bag OFF indicator light is normal.

Q: Is the check result normal?

YES : Go to Step 4.

NO : Replace center panel assembly.

STEP 4. Check the harness for open circuit between SRS-ECU connector C-28 (terminal No.18) and the center panel assembly connector C-104 (terminal No.11).

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.
3. Disconnect the center panel assembly connector C-104.

4. Check for continuity between the following terminals. It should be less than 2 ohms.

• SRS-ECU connector C-28 (terminal No.18) and the center panel assembly connector C-104 (terminal No.11)

Q: Does continuity exist?

YES : Go to Step 5.

NO : Repair the harness wires.

STEP 5. Measure the voltage at the center panel assembly connector.

1. Disconnect the negative battery terminal.
2. Disconnect the C-104 center panel assembly connector.
3. Connect the negative battery terminal.
4. Ignition switch: ON.
5. Measure the voltage between the C-104 harness side connector terminal No. 8 and body ground.

• The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES : Go to Step 6.

NO : Repair the wiring harness between the C-317 ETACS-ECU connector terminal No. 5 and the C-104 instrument center panel assembly connector terminal No. 8.

STEP 6. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1206 set?

YES : Replace SRS-ECU.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

DTC B1207: Passenger's Air Bag OFF Indicator Light (Short Circuit between Circuit Terminal)

Air Bag OFF Indicator Light Drive Circuit

CAUTION If DTC B1207 is set in the SRS-ECU, always diagnose the CAN main bus line.

CIRCUIT OPERATION

• Power for the passenger's air bag OFF indicator light is supplied from the fusible link (34).
• The passenger's air bag OFF indicator light illuminates when the ignition switch is turned to the "ON" position and goes out after approximately seven seconds if there is not a malfunction in the SRS system. In the following situations, the indicator will stay on to show that the passenger's (front) air bag is not operational.
  • The occupant is determined to be less than 66 lbs (30 kg) by the occupant classification- ECU.
  • The front passenger's seat is not occupied.

DTC SET CONDITIONS

This DTC will be set if the passenger's air bag OFF indicator light driving circuit is short to ground. If the vehicle condition returns to normal, DTC B1207 will be automatically erased, and the warning light will go out.

TROUBLESHOOTING HINTS

• Damaged wiring harnesses or connectors
• Malfunction of the SRS-ECU
• Malfunction of the passenger's air bag OFF indicator light

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool".
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check the passenger's air bag OFF indicator light.

1. It is checked whether the passenger's air bag OFF indicator light is normal.

Q: Is the check result normal?

YES : Go to Step 4.

NO : Replace center panel assembly.

STEP 4. Resistance measurement at the C-28 SRS-ECU connector.

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.
3. Disconnect the center panel assembly connector C-104.

4. Take the measurements below at the SRS-ECU harness side connector. It should be open circuit.

• Continuity between terminal No.18 and body ground

Q: Is it open circuit?

YES : Go to Step 5.

NO : Repair the wiring harness between the C-28 SRS-ECU connector terminal No. 18 and the C-104 center panel assembly connector terminal No.11.

Then go to Step 6

STEP 5. Resistance measurement at the C-28 SRS-ECU connector.

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

CAUTION Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

3. Check for continuity between the C-28 harness side connector terminal No.18 and body ground.

   It should be open circuit.

Q: Is it open circuit?

YES : Go to Step 6.

NO : Replace SRS-ECU.

STEP 6. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1207 set?

YES : Replace SRS-ECU.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

DTC B1B00: Driver's Air Bag Module (1st Squib) System (Shorted to Squib Circuit Ground)
DTC B1B04: Driver's Air Bag Module (2nd Squib) System (Shorted to Squib Circuit Ground)

Drivers's Air Bag Module (Squib) Circuit

CAUTION

• If DTC B1B00 <1st squib> or B1B04 <2nd squib> is set in the SRS-ECU, always diagnose the CAN main bus line.
• When DTC B1B00 is set in the following diagnosis, check the 1st squib circuit. When DTC B1B04 is set, check the 2nd squib circuit.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
• The ignition signal is sent to the air bag module via the clock spring to inflate the air bag.

DTC SET CONDITIONS

This DTC is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib).

TROUBLESHOOTING HINTS

• Malfunction of the clock spring
• Damaged harness wires and connectors
• Short to the ground in the driver's air bag module (squib) harness
• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)
• MB991865: Dummy resistor
• MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check the driver's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Slide the outer housing of the clock spring side of the driver' s air bag module connector C-205 in the arrow direction shown, and disconnect the connector.

3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring side air bag module connector C-205 (terminal No.1 and 2 <1st squib> or terminal No.3 and 4 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B00. This is because the second side terminal is isolated when checking it, DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B04 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 4.

NO : Replace the driver's air bag module.

STEP 4. Check the clock spring. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Disconnect the clock spring connector C-207.
3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring harness side connector C-207 (terminal No. 3 and 4 <1st squib> or terminal No. 1 and 2 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B00. This is because the second side terminal is isolated when checking it, DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B04 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 5.

NO : Replace the clock spring. Then go to Step 7.

STEP 5. Check the driver's air bag module circuit. Measure the resistance at the SRS-ECU connector C-28.

1. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

DANGER To prevent the air bag from deploying unintentionally, disconnect the clock spring connector C-207 to short the squib circuit.

2. Disconnect the clock spring connector C-207.

CAUTION Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not be released.

3. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 <1st squib> or 9, 10 <2nd squib> and the short spring to release the short spring.

4. Check for continuity between C-28 harness side connector terminals 5 and 6 <1st squib> or 9 and 10 <2nd squib> and body ground.

   It should be open circuit.

Q: Is it open circuit?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B00 <1st squib> or B1B04 <2nd squib> sets, replace the SRS-ECU. Go to Step 7.

NO : Go to Step 6.

STEP 6. Check the harness for short circuit to ground between the following connector.

• SRS-ECU connector C-28 (terminal No.5 and 6) and clock spring connector C-207 (terminal No.4 and 3) <1st squib>.
• SRS-ECU connector C-28 (terminal No.9 and 10) and clock spring connector C-207 (terminal No.1 and 2) <2nd squib>.

Q: Is the check result normal?

YES : Go to Step 7.

NO : Repair the harness wires between SRS-ECU connector C-28 and clock spring connector C-207.

Then go to Step 7.

STEP 7. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1B00 <1st squib> or B1B04 <2nd squib> set?

YES : Return to Step 1.

NO : The procedure is complete.

DTC B1B01: Driver's Air bag Module (1st squib) System (Shorted to Squib Circuit Power Supply)
DTC B1B05: Driver's Air bag Module (2nd squib) System (Shorted to Squib Circuit Power Supply

Drivers's Air Bag Module (Squib) Circuit

CAUTION

• If DTC B1B01 <1st squib> or B1B05 <2nd squib> is set in the SRS-ECU, always diagnose the CAN main bus line.
• When DTC B1B01 is set in the following diagnosis, check the 1st squib circuit. When DTC B1B05 is set, check the 2nd squib circuit.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
• The ignition signal is input to the air bag module via the clock spring to inflate the air bag.

DTC SET CONDITIONS

This DTC is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib).

TROUBLESHOOTING HINTS

• Malfunction of the clock spring
• Damaged harness wires and connectors
• Short to the power supply in the driver's air bag module (squib) harness
• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)
• MB991865: Dummy resistor
• MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool".
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check the driver's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Slide the outer housing of the clock spring side of the driver' s air bag module connector C-205 in the arrow direction shown, and disconnect the connector.

3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring side air bag module connector C-205 (terminal No.1 and 2 <1st squib> or terminal No.3 and 4 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B01. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B05 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 4.

NO : Replace the driver's air bag module.

STEP 4. Check the clock spring. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Disconnect the clock spring connector C-207.
3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring harness side connector C-207 (terminal No.3 and 4 <1st squib> or terminal No. 2 and 1 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B01. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B05 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 5.

NO : Replace the clock spring. Then go to Step 7.

STEP 5. Check the driver's air bag module circuit. Measure the voltage at the SRS-ECU connector C-28.

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

DANGER To prevent the air bag from deploying unintentionally, disconnect the clock spring connector C-207 to short the squib circuit.

3. Disconnect the clock spring connector C-207.

CAUTION Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not be released.

4. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 <1st squib> or 9, 10 <2nd squib> and the short spring to release the short spring.
5. Connect the negative battery terminal.
6. Ignition switch: ON.

7. Measure the voltage between C-28 harness side connector terminals 5 and 6 <1st squib> or 9 and 10 <2nd squib> and body ground.

   Voltage should measure 1 volt or less.

Q: Is the measured voltage within the specified range?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B01 <1st squib> or B1B05 <2nd squib> sets, replace the SRS-ECU. Then go to Step 7.

NO : Go to Step 6.

STEP 6. Check the harness for short circuit to power supply between the following connector.

• SRS-ECU connector C-28 (terminal No.5 and 6) and clock spring connector C-207 (terminal No.4 and 3) <1st squib>.
• SRS-ECU connector C-28 (terminal No.9 and 10) and clock spring connector C-207 (terminal No.1 and 2) <2nd squib>.

Q: Is the check result normal?

YES : Go to Step 7.

NO : Repair the harness wires between SRS-ECU connector C-28 and clock spring connector C-207.

Then go to Step 7.

STEP 7. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1B01 <1st squib> or B1B05 <2nd squib> set?

YES : Return to Step 1.

NO : The procedure is complete.

DTC B1B02: Driver's Air Bag Module (1st squib) System (Squib Circuit Open)
DTC B1B06: Driver's Air Bag Module (2nd squib) System (Squib Circuit Open)

Drivers's Air Bag Module (Squib) Circuit

CAUTION

• If DTC B1B02 <1st squib> or B1B06 <2nd squib> is set in the SRS-ECU, always diagnose the CAN main bus line.
• When DTC B1B02 is set in the following diagnosis, check the 1st squib circuit. When DTC B1B06 is set, check the 2nd squib circuit.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
• The ignition signal is input to the air bag module via the clock spring to inflate the air bag.

DTC SET CONDITIONS

• This DTC is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib). The most likely causes for this code to be set are the followings:
  • Open circuit in the driver's air bag module (squib) or harness
  • Open circuit in the clock spring
  • Malfunction of connector contact

TROUBLESHOOTING HINTS

• Open circuit in the clock spring
• Open circuit due to improper neutral position of the clock spring
• Open circuit in the driver's air bag module (squib) circuit
• Disengaged driver's air bag module (squib) connector
• Improper connector contact
• Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN Communication System)
• MB991865: Dummy resistor
• MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool".
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check the driver's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Slide the outer housing of the clock spring side of the driver' s air bag module connector C-205 in the arrow direction shown, and disconnect the connector.

3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring side of driver's air bag module connector C-205 (terminal No.1 and 2 <1st squib> or terminal No.3 and 4 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B02. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B06 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 4.

NO : Replace the driver's air bag module. Then go to Step 6.

STEP 4. Check the clock spring. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Disconnect the clock spring connector C-207.
3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into harness side of clock spring connector C-207 (terminal No.3 and 4 <1st squib> or terminal No.1 and 2 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B02. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B06 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 5.

NO : Replace the clock spring. Then go to Step 6.

STEP 5. Check the harness for open circuit between the SRS-ECU connector C-28 and the clock spring connector C-207.

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

DANGER To prevent the air bag from deploying unintentionally, disconnect the clock spring connector C-207 to short the squib circuit.

3. Disconnect the clock spring connector C-207.

CAUTION Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not be released.

4. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 <1st squib> or 9, 10 <2nd squib> and the short spring to release the short spring.

CAUTION Do not insert a probe into the terminal from C-207 harness side connector front side directly, as the connector contact pressure may be weakened.

5. Check for continuity between the following terminals. It should be less than 2 ohms.

<1st squib>

• SRS-ECU connector C-28 (terminal No.5) and the clock spring connector C-207 (terminal No.4)
• SRS-ECU connector C-28 (terminal No.6) and the clock spring connector C-207 (terminal No.3)

<2nd squib>

• SRS-ECU connector C-28 (terminal No.9) and the clock spring connector C-207 (terminal No.1)
• SRS-ECU connector C-28 (terminal No.10) and the clock spring connector C-207 (terminal No.2)

Q: Does continuity exist?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B02 <1st squib> or B1B06 <2nd squib> set, replace the SRS-ECU. Then go to Step 6.

NO : Repair the harness wires between SRS-ECU connector C-28 and clock spring connector C-207.

Then go to Step 6.

STEP 6. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1B02 <1st squib> or B1B06 <2nd squib> set?

YES : Return to Step 1.

NO : The procedure is complete.

DTC B1B03: Driver's Air Bag Module (1st squib) System (Short Circuit Between Squib Circuit Terminals)
DTC B1B07: Driver's Air Bag Module (2nd squib) System (Short Circuit Between Squib Circuit Terminals)

Drivers's Air Bag Module (Squib) Circuit

CAUTION

• If DTC B1B03 <1st squib> or B1B07 <2nd squib> is set in the SRS-ECU, always diagnose the CAN bus lines.
• When DTC B1B03 is set in the following diagnosis, check the 1st squib circuit. When DTC B1B07 is set, check the 2nd squib circuit.

CIRCUIT OPERATION

• The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU sends an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
• The ignition signal is input to the air bag module via the clock spring to inflate the air bag.

DTC SET CONDITIONS

• This DTC is set if there is abnormal resistance between the input terminals of the driver's air bag module (squib). The most likely causes for this code to be set are the followings:
  • Short circuit in driver's air bag module (squib) or harness
  • Short circuit in the clock spring

TROUBLESHOOTING HINTS

• Improper engaged connector or defective short spring*
• Short circuit in the clock spring
• Short circuit between the driver's air bag module (squib) circuit terminals
• Damaged connector(s)
• Malfunction of the SRS-ECU

NOTE: *: The squib circuit connectors integrate a "short" spring (which prevents the air bag from deploying unintentionally due to static electricity by shorting the positive wire to the ground wire in the squib circuit when the connectors are disconnected).

Therefore, if connector C-28, C-205 or C-207 is damaged or improperly engaged, the short spring may not be released when the connector is connected.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
• MB991865: Dummy resistor
• MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958. Refer to "How to connect the scan tool".
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Go to Step 3.

NO : There is an intermittent malfunction such as poor engaged connector(s) or open circuit.

STEP 3. Check SRS-ECU connector C-28, driver's air bag module connector C-205 and clock spring connector C-207. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Disconnect connectors C-28, C-205 and C-207, and then reconnect them.

• While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

• Slide the outer housing of the clock spring side of driver's air bag module connector C-205 in the arrow direction shown, and disconnect the connector.

3. Connect the negative battery terminal.
4. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is DTC B1B03 <1st squib> or B1B07 <2nd squib> set?

YES : Go to Step 4.

NO : The procedure is complete. It is assumed that DTC B1B03 <1st squib> or B1B07 <2nd squib> set because connector C-28, C-205 or C-207 was engaged improperly.

STEP 4. Check the driver's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Slide the outer housing of the C-205 driver's air bag module connector in the arrow direction shown, and disconnect the connector.

3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a probe into the terminal from its front side directly as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring side of driver's air bag module connector C-205 (terminal No.1 and 2 <1st squib> or No.3 and 4 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B03. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B07 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 5.

NO : Replace the driver's air bag module. Then go to Step 8.

STEP 5. Check the clock spring. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.
2. Disconnect the clock spring connector C-207.
3. Connect special tool MB991865 to special tool MB991866.

CAUTION Do not insert a probe into the terminal from C-207 harness side connector front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into clock spring harness side connector C-207 (terminal No.3 and 4 <1st squib> or No.1 and 2 <2nd squib>) by backprobing.
5. Connect the negative battery terminal.

CAUTION Always DTC B1B06 is set when checking DTC B1B03. This is because the second side terminal is isolated when checking it. DTC B1B06 is set but this is not a fault. In addition, always DTC B1B02 is set when checking DTC B1B07 because the first side terminal is isolated.

6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is the checked DTC set?

YES : Go to Step 6.

NO : Replace the clock spring. Then go to Step 8.

STEP 6. Check the driver's air bag module circuit. Measure the resistance at SRS-ECU connector C-28.

1. Disconnect the negative battery terminal.
2. While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-28 SRS-ECU connector.

DANGER To prevent the air bag from deploying unintentionally, disconnect clock spring connector C-207 to short the squib circuit.

3. Disconnect clock spring connector C-207.

CAUTION Insert an insulator such as a cable tie to a depth of 4mm (0.16 inch) or more, otherwise the short spring will not be released.

4. Insert a cable tie [3 mm (0.12 inch) wide, 0.5 mm (0.02 inch) thick] between terminals 5, 6 <1st squib> or 9, 10 <2nd squib> and the short spring to release the short spring.

5. Check for continuity between C-28 harness side connector terminals 5 and 6 <1st squib> or 9 and 10 <2nd squib>.

   It should be open circuit.

Q: Is it open circuit?

YES : Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1B03 <1st squib> or B1B07 <2nd squib> set, replace the SRS-ECU. Go to Step 8.

NO : Go to Step 7.

STEP 7. Check the harness for short circuit between the harness wire and wire.

• SRS-ECU connector C-28 (terminal No.5 and 6) and clock spring connector C-207 (terminal No.4 and 3) <1st squib>.
• SRS-ECU connector C-28 (terminal No.9 and 10) and clock spring connector C-207 (terminal No.1 and 2) <2nd squib>.

Q: the check result normal?

YES : Go to Step 8.

NO : Repair the harness wires between SRS-ECU connector C-28 and clock spring connector C-207.

Then go to Step 8.

STEP 8. Recheck for diagnostic trouble code.

Check again if the DTC is set.

1. Erase the DTC.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC B1B03 <1st squib> or B1B07 <2nd squib> set?

YES : Return to Step 1.

NO : The procedure is complete.

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