Code No. P0988: Low-Reverse Brake Pressure Switch System


DIAGNOSIS CODE SET CONDITIONS


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.)
note *1 Indicates the series of driving cycle in the order of "ignition key OFF, ON, drive and OFF." The "1 driving cycle," "2 driving cycle," and so on indicates how many cycles are required to detect a failure.

PROBABLE CAUSES



caution For the incomplete gear shifting and slippage, first refer to the SYMPTOM CHART .

DIAGNOSIS PROCEDURE

STEP 1. Check the diagnosis code.

Q. Is the diagnosis code other than the pressure switch set? (Is the code other than P0846, P0876, and P0988 set?)
Check and repair the relevant diagnosis code system.
Go to Step 2.

STEP 2. Check the A/T-ECU terminal voltage.
[A/T-ECU connector (harness side, connected)]
Measure the voltage between LRPS terminal and body earth.

  • Low-reverse brake engaged: 0 V
  • Other than above: System voltage

Q. Is the check result normal?
Go to Step 3.
Go to Step 7.

STEP 3. Check for continuity in LRPS line between the A/T-ECU connector and the A/T control solenoid valve assembly.
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?
Go to Step 4.
Repair the connector(s) or wiring harness.

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

Q. Is the check result normal?
Go to Step 5.
Repair or replace the failure section.

STEP 5. Check for continuity in signal line between the A/T control solenoid valve assembly connector and the low-reverse brake pressure switch.
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?
Go to Step 6.
Repair the connector(s) or wiring harness.

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

  • Between the low-reverse brake pressure switch body and body earth: Continuity exists.

Q. Is the check result normal?
Replace the valve body assembly, and then go to Step 8.
Repair or replace the failure section.

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

Q. Is the check result normal?
Go to Step 9.
Repair or replace the failure section.

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

Q. Is the check result normal?
The procedure is complete.
Replace the A/T-ECU.

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

Q. Is the check result normal?
The procedure is complete.
Return to Step 1.