DTC B1812

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DTC B1812

B3E090201072W26

DTC B1812 | Backup light switch input circuit short to battery
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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
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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)
(See BACK-UP LIGHT SWITCH INSPECTION.)
• Inspect the TR switch. (ATX)
(See TRANSAXLE RANGE (TR) SWITCH INSPECTION.)
• Is there any malfunction?

Yes

Replace the back-up light switch (MTX) or TR switch (ATX), then go to the next step.
(See BACK-UP LIGHT SWITCH REMOVAL/INSTALLATION.)
(See TRANSAXLE RANGE (TR) SWITCH REMOVAL/INSTALLATION.)

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.
(See PASSENGER JUNCTION BOX (PJB) REMOVAL/INSTALLATION.)

No | DTC troubleshooting completed.