Engine Speed Does Not Return to Idle

15. Engine Speed Does Not Return To Idle (Light Braking D4 -> D3

SYMPTOM: Engine speed does not smoothly return to idle when A/T shifts from D4 to D3.
Vehicle does not decelerate by engine brake when turning overdrive control switch OFF.
Vehicle does not decelerate by engine brake when shifting A/T from D to 2 position.







1. CHECK SELF-DIAGNOSTIC RESULTS
Does self-diagnosis show damage to overrun clutch solenoid valve circuit after cruise test?

Yes or No?

Yes >> Check overrun clutch solenoid valve circuit. Refer to "P1760; Diagnostic Procedure" P1760.

No >> GO TO 2.







2. CHECK THROTTLE POSITION SENSOR
Check throttle position sensor. Refer to "DTC P0121 TP SENSOR" P0121.

OK or NG?

OK >> GO TO 3.

NG >> Repair or replace throttle position sensor.







3. CHECK A/T FLUID CONDITION
1. Remove oil pan.
2. Check A/T fluid condition.

OK or NG?

OK >> GO TO 4.

NG >> GO TO 6.


4. DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly.
2. Check the following items:
- Overrun clutch control valve
- Overrun clutch reducing valve
- Overrun clutch solenoid valve

OK or NG?

OK >> GO TO 5.

NG >> Repair or replace damaged parts.


5. CHECK SYMPTOM
Check again.

OK or NG?

OK >> INSPECTION END.

NG >>
1. Perform TCM input/output signal inspection Pinout Values and Diagnostic Parameters.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.


6. DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly.
2. Check the following items:
- Overrun clutch control valve
- Overrun clutch reducing valve
- Overrun clutch solenoid valve

3. Disassemble A/T.
4. Check the following items:
- Overrun clutch assembly
- Oil pump assembly

OK or NG?

OK >> GO TO 5.

NG >> Repair or replace damaged parts.