30

Does not downshift in M position

DESCRIPTION

• Gear position indication in instrument cluster illuminates, but the vehicle does not downshift when the selector lever is pushed to “–” side or steering shift switch “DOWN” is pushed.

POSSIBLE CAUSE

• Down switch or related wiring harness malfunction

• Steering shift switch (DOWN) or related circuit malfunction.

STEP

INSPECTION

ACTION

1

• Access TCM PID M_DOWN using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [TCM (SJ6A-EL)].)

• Monitor the PID at the selector lever is pushed to “-” side.

• Are PID values normal?

Yes

Go to the next step.

No

Inspect the down switch.

(See DOWN SWITCH INSPECTION [SJ6A-EL].)

If the down switch has a malfunction:

• Replace the selector lever component.

  (See AUTOMATIC TRANSMISSION SHIFT MECHANISM REMOVAL/INSTALLATION.)

If the down switch is normal:

• Inspect for continuity the followings:

• Between selector lever component terminal F (down switch signal) and TCM terminal 2F.

• Between selector lever component terminal A and ground.

• Repair or replace the suspected wiring harness.

2

• Access TCM PID PADDLE_DOWN using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM PID/DATA MONITOR INSPECTION [TCM (SJ6A-EL)].)

• Monitor the PID at the steering shift switch “DOWN” is pushed.

• Are PID values normal?

Yes

Inspect the instrument cluster.

(See INSTRUMENT CLUSTER INSPECTION.)

Replace the instrument cluster, if necessary.

(See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)

No

Inspect the steering shift switch.

(See STEERING SHIFT SWITCH INSPECTION [SJ6A-EL].)

If the steering shift switch has a malfunction:

• Replace the steering shift switch.

  (See STEERING SHIFT SWITCH REMOVAL/INSTALLATION [SJ6A-EL].)

If the steering shift switch is normal:

• Inspect for continuity the followings:

• Between audio control switch terminal F (steering shift switch signal) and TCM terminal 2AF.

• Between audio control switch terminal C (steering shift switch ground) and TCM terminal 2AB.

• Repair or replace the suspected wiring harness.

3

• Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If 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 [SJ6A-EL].)