P0988

DTC P0988: Low-Reverse Brake Pressure Switch System

PRESSURE SWITCH SYSTEM CIRCUIT
Refer to DTC P0841. P0841

DESCRIPTIONS OF MONITOR METHODS
^ During reverse driving, the switch OFF status continues for 2 seconds. (The detection is achieved twice during 1 driving cycle *1, and it continues for 2 driving cycles.)
*1: Indicates the series of driving cycle "ignition key OFF ON drive OFF." The "1 driving cycle," "2 driving cycle," and so on indicates how many cycles are required to detect a failure.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
^ Malfunction of the low-reverse brake pressure switch system circuit
^ Damaged harness or connector
^ Malfunction of the TCM
^ Malfunction of the low-reverse brake pressure switch system (valve body assembly)
^ Malfunction of the valve body assembly, abnormal hydraulic circuit valve.

CAUTION: For the incomplete gear shifting and slippage, first refer to the SYMPTOM CHART. Symptom Chart

DIAGNOSIS

STEP 1. Check the DTC.

Q:Is the DTC other than the pressure switch set? (Is the code other than P0841, P0846, P0871, P0876, and P0988 set?)
YES: Check and repair the relevant DTC system.
NO: Go to Step 2.

STEP 2. Check the TCM terminal voltage.
[C-37 TCM connector (vehicle side, connected)]

Measure the voltage between C-37 terminal No. 43 and body ground.

^ Low-reverse brake engaged: 0 V
^ Other than above: Battery positive voltage

Q:Is the check result normal?
YES: Go to Step 3.
NO: Go to Step 7.

STEP 3. Check between the TCM connector and A/T control solenoid valve assembly.
Check for continuity between C-37 TCM connector and B-111 A/T control solenoid valve assembly connector.

^ Between C-37 terminal No. 43 and B-111 terminal No. 7: Continuity exists.

When the continuity check result is OK, check that the wiring harness is not shorted to the body and other wiring harness.

Q:Is the check result normal?
YES: Go to Step 4.
NO: Repair or replace the failure section.

STEP 4. Check the TCM, A/T control solenoid valve assembly connector pin terminals, and the connection status.

Q:Is the check result normal?
YES: Go to Step 5.
NO: Repair or replace the failure section.

STEP 5. Check between the A/T control solenoid valve assembly connector and low-reverse brake pressure switch.
Check for continuity between the B-111 A/T control solenoid valve assembly connector terminals and the low-reverse brake pressure switch connector terminals.

^ Between B-111 terminal No. 7 and low-reverse brake pressure switch: Continuity exists.

When the continuity check result is OK, check that the wiring harness is not shorted to the body and other wiring harness.

Q:Is the check result normal?
YES: Go to Step 6.
NO: Repair or replace the failure section.

STEP 6. Check the low-reverse brake pressure switch body ground.
Check for continuity between the low-reverse brake pressure switch body and ground.

^ Between the low-reverse brake pressure switch body and body ground: Continuity exists.

Q:Is the check result normal?
YES: Replace the valve body assembly, and then go to Step 8.
NO: Repair or replace the failure section.

STEP 7. Check the TCM, A/T control solenoid valve assembly connector pin terminals, and the connection status.

Q:Is the check result normal?
YES: Go to Step 9.
NO: Repair or replace the failure section.

STEP 8. Erase the DTC code, and drive the vehicle for a while.
Check that the normal code is displayed.

Q:Is the check result normal?
YES: The procedure is complete.
NO: Replace the TCM.

STEP 9. Erase the DTC code, and drive the vehicle for a while.
Check that the normal code is displayed.

Q:Is the check result normal?
YES: The procedure is complete.
NO: Return to START.