Code No. P1794: Earth Return


DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES



  • Breakage of earth return wire
  • Damaged harness or connector
  • Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check between the A/T-ECU connector and body earth.
Check for continuity between C-138 A/T-ECU connector terminal No. 16 and body earth.

  • Between C-138 terminal No. 16 and body earth: Continuity exists.
Check for continuity between the C-138 A/T-ECU connector terminal No. 16 and the C-138 A/T-ECU connector terminal No. 13 and No. 26.

  • Between C-138 terminal No. 16 and C-138 terminal No. 13 and No. 26: Continuity exists.

Q. Is the check result normal?
Go to Step 6.
Go to Step 2.

STEP 2. Check the wiring harness between A/T-ECU and the A/T control solenoid valve assembly.
Check for continuity between C-138 A/T-ECU connector and B-132 A/T control solenoid valve assembly connector.

  • Between C-138 terminal No. 16 and B-132 terminal No. 13: 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?
Go to Step 3.
Repair or replace the failure section.

STEP 3. Check the wiring harness between the A/T control solenoid valve assembly and body earth.
Check for continuity between B-132 A/T control solenoid valve assembly and body earth.

  • Between B-132 terminal No. 13 and body earth: 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?
Go to Step 5.
Go to Step 4.

STEP 4. Check the wiring harness between the A/T control solenoid valve assembly terminals and earth terminals.
Check for continuity between B-132 A/T control solenoid valve assembly terminals and earth terminals.

  • Between B-132 terminal No. 13 and earth: 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?
Go to Step 5.
Repair or replace the failure section.

STEP 5. Check the A/T-ECU, A/T control solenoid valve assembly connector pin terminals, and the connection status.

Q. Is the check result normal?
Replace the A/T-ECU.
Repair or replace the failure section.

STEP 6. 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 7.
Repair or replace the failure section.

STEP 7. 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 START.