DTC B1812


id0902j0834700

DTC B1812

Backup light switch input circuit short to battery

DETECTION CONDITION

Short to power supply in wiring harness between PJB and back-up light switch

POSSIBLE CAUSE

• Short to power supply in wiring harness between PJB terminal J-01 AE and back-up light switch terminal B (MTX)
• Short to power supply in wiring harness between PJB terminal J-01 AE and TR switch terminal D (ATX)
• Back-up light switch malfunction (MTX)
• TR switch malfunction (ATX)
• PJB malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT BACK-UP LIGHT SWITCH CONNECTOR
• Turn the ignition switch off.
• Disconnect the back-up light switch connector. (MTX)
• Disconnect the TR switch connector. (ATX)
• Inspect the switch connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 5.
No
Go to the next step.
2
INSPECT PJB CONNECTOR
• Disconnect the PJB connector.
• Inspect the PJB connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 5.
No
Go to the next step.
3
INSPECT BACK-UP LIGHT SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
• Turn the ignition switch to the ON position (Engine off).
• Measure the voltage between PJB terminal J-01 AE (wiring harness-side) and body GND.
• Is the voltage B+?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 5.
No
Go to the next step.
4
INSPECT BACK-UP LIGHT SWITCH
• Inspect the back-up light switch. (MTX)
• Inspect the TR switch. (ATX)
• Is there any malfunction?
Yes
Replace the back-up light switch (MTX) or TR switch (ATX), then go to the next step.
No
Go to the next step.
5
VERIFY TROUBLESHOOTING COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PJB memory using the WDS or equivalent.
• Perform the self-test.
(See PJB SELF-TEST.)
• Is the same DTC present?
Yes
Replace the PJB.
No
DTC troubleshooting completed.