Inspection Procedure 1: TCM cannot communication with scan tool.
TCM POWER SUPPLY CIRCUIT
SYMPTOMS
TCM cannot be turned ON.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. Check the following connector:
Check each terminal for imperfect contact.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the defective connector.
STEP 2. Check for open circuit in the wiring harness between the relay box connector and the TCM connector.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the wiring harness.
STEP 3. Check for open circuit in the wiring harness between the TCM connector and the ground.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the wiring harness.
STEP 4. Retest the system.
Recheck the trouble symptom.
Q: Does the malfunction take place again?
YES : Replace TCM.
NO : Intermittent malfunction
Inspection Procedure 2: Vehicle Creeps in the N Range.
SYMPTOMS
Engine torque is transferred to the driveshaft in the N range, and the vehicle consequently moves forward or rearward.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
Item 49: Transmission range switch
Check that the service data changes when the selector lever is moved to all ranges.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Go to Step 3.
STEP 2. Check of the transmission range switch and shift control cable
Q: Is the check result normal?
YES : Go to Step 4.
NO : Adjust the transmission range switch and the control cable.
STEP 3. Transmission range switch continuity check
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the transmission range switch.
STEP 4. Retest the system.
Q: Does the malfunction take place again?
YES : Replace the CVT assembly.
NO : The inspection is complete.
Inspection Procedure 3: Shock is experienced during N to D and/or N to R shifting operation.
SYMPTOMS
Deep shock is experienced when the selector lever is moved from the N to R range or from the N to D range.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. Engine idling speed check
Q: Is the check result normal?
YES : Go to Step 2.
NO : Refer to the "Engine troubleshooting". STEP 2. Line pressure check
Carry out "hydraulic test".
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair according to the hydraulic pressure test diagnosis table.
STEP 3. Retest the system.
Q: Does the malfunction take place again?
YES : Replace the CVT assembly.
NO : The inspection is complete.
Inspection Procedure 4: Poor Acceleration or Incomplete Shifting Operation
SYMPTOMS
Vehicle does not creep. Incomplete shifting operation or extremely poor acceleration is observed.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. Engine-related troubleshooting check
Check for engine malfunction.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Carry out the engine-related troubleshooting.
STEP 2. Torque converter stall test implementation
Q: Is the check result normal?
YES : Go to Step 3.
NO (stall speed is low.) : Replace the torque converter.
NO (stall speed is high.) : Go to Step 4.
STEP 3. Forward clutch pressure check
Carry out "hydraulic test".
Q: Is the check result normal?
YES : Replace the forward clutch.
NO : Replace the valve body assembly.
STEP 4. Retest the system.
Replace TCM, and then recheck symptoms.
Q: Does the malfunction take place again?
YES : Replace the CVT assembly.
NO : The inspection is complete.
Inspection Procedure 5: Cannot be Changed in Sport Mode.
Shift switch assembly system circuit
SYMPTOMS
Gears cannot be changed even when the selector lever is moved to "+" or "−" position during sport mode.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
Q: Is the check result normal?
YES : Intermittent malfunction
NO : Go to Step 2.
STEP 2. Shift switch assembly single unit check
Q: Is the check result normal?
YES : Go to Step 3.
NO : Replace the selector lever assembly.
STEP 3. Check the following connector:
Check the terminals for a contact status problem and internal short circuit.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Repair the connector concerned.
STEP 4. Check for open circuit and short to ground in the wiring harness between the selector lever assembly connector and the TCM connector.
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Retest the system.
Q: Does the malfunction take place again?
YES : Replace TCM.
NO : Intermittent malfunction
Inspection Procedure 6: Cannot be Changed with the Paddle Shift.
Paddle shift switch system circuit
SYMPTOMS
The transaxle does not upshift or downshift when the paddle shift is operated.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III data list
Q: Is the check result normal?
YES : Intermittent malfunction
NO : Go to Step 2.
STEP 2. Check the following connector:
Check the contact status of the terminals.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Repair the damaged connector.
STEP 3. Paddle shift switch single unit check
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the paddle shift assembly.
STEP 4. Check for open circuit in the wiring harness between the TCM connector and the paddle shift switch connector
Q: Is the check result normal?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Retest the system.
Q: Is the check result normal?
YES : Intermittent malfunction
NO : Replace TCM.
Inspection Procedure 7: The fluid temperature warning lamp illuminates too frequently.
PROBABLE CAUSES
DIAGNOSTIC PROCEDURE
STEP 1. Scan tool MB991958 special function
Check the deterioration level of the transmission fluid.
NOTE: The transmission fluid deterioration level is the accumulation of the values counted depending on the fluid temperature of a certain period of time, and it shows the thermal deterioration level of the transmission fluid.
Q: Is the deterioration level of the transmission fluid less than 210,000?
YES : Go to Step 2.
NO : Replace the transmission fluid.
STEP 2. M.U.T.-III data list
Item 5: Transmission fluid temperature sensor.
Q: Is the check result normal?
YES : Go to Step 3.
NO : Diagnostic trouble code No.P0710: Diagnose the transmission fluid temperature sensor.
STEP 3. Air-cooled transmission fluid cooler system clogging check
Check if the air-cooled transmission fluid cooler system is clogged according to the following procedure.
CAUTION Do not reuse the drained transmission fluid.
Q: Is the check result normal?
YES : Go to Step 4.
NO : Replace the part(s) having damage or other problems.
STEP 4. Thermo valve check
Q: Is the check result normal?
YES : Go to Step 5.
NO : Replace the thermo valve.
STEP 5. Coolant system clogging check
Check if the coolant system is clogged according to the following procedure.
CAUTION Do not reuse the drained coolant.
Q: Is the check result normal?
YES : Go to Step 6.
NO : Replace the part(s) having damage or other problems.
STEP 6. Retest the system.
Q: Does a malfunction take place again?
YES : Replace the CVT assembly.
NO : Intermittent malfunction
DATA LIST REFERENCE TABLE
NOTE: *: Relation between fluid temperature and COUNT is shown to the characteristics chart.
TCM TERMINAL VOLTAGE REFERENCE CHART FOR TRANSAXLE OPERATION
OSCILLOSCOPE INSPECTION PROCEDURES
With the connector remain connected, connect the oscilloscope probe to each terminal of TCM.
Special Tool