NO.24 NO ENGINE BRAKING IN 1GR POSITION OF M RANGE


BHE050301026W29

24

No engine braking in 1GR position of M range

DESCRIPTION

• Engine speed drops to idle but vehicle coasts when accelerator pedal is released when in 1GR of M range at low vehicle speed.

POSSIBLE CAUSE

• Clutch slippage (low and reverse brake)
– In the event of clutch slippage, a DTC (incorrect gear ratio) is output.
• Input/output signal malfunction
– M range switch (short or open circuit, poor connection)
– Shift solenoid F
• Control valve body malfunction (improper operation, stuck)
– Hydraulic circuit clogging (Shift solenoid F)
Note
• Before following the troubleshooting steps, make sure that the Automatic Transmission On-Board Diagnostic and Automatic Transmission Basic Inspection are conducted. (See BASIC INSPECTION.)

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Do the following symptoms concurrently occur?
• Engine flares up or slips during acceleration.
• Engine flares up or slips when shifting.
Yes
Go to symptom troubleshooting NO.16 "ENGINE FLARES UP OR SLIPS WHEN UPSHIFTING OR DOWNSHIFTING" or No.17 "ENGINE FLARES UP OR SLIPS WHEN ACCELERATING VEHICLE".
No
Repeat the basic inspection and repair or replace any malfunctioning parts according to the inspection result.
2
Verify the test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
– If the vehicle is repaired, troubleshooting completed.
– If the vehicle is not repaired or additional diagnostic information is not available, replace the TCM.
(See TCM REMOVAL/INSTALLATION.)