DTC B1A79:11 [ELECTRICAL SUPPLY UNIT (ESU)]
id0902ff061800
Description |
Rear fog light circuit malfunction |
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Detection condition
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• Electrical supply unit (ESU) detects a short to ground in the rear fog light circuit with the ignition switched ON (engine off or on).
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Fail-safe
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Not applicable
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Possible cause
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• Rear fog light bulb malfunction
• Rear fog light connector or terminal malfunction
• Electrical supply unit (ESU) connector or terminal malfunction
• Short to ground in wiring harness between rear fog light terminal A and electrical supply unit (ESU) terminal 2C
• Electrical supply unit (ESU) malfunction
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Diagnostic Procedure
Step |
Inspection |
Action |
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1
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VISUALLY INSPECT REAR FOG LIGHT BULB
• Visually inspect the rear fog light bulb.
• Is the rear fog light bulb normal?
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Yes
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Go to the next step.
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No
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Replace the rear fog light bulb, then go to Step 5.
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2
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INSPECT REAR FOG LIGHT CONNECTOR CONDITION
• Switch the ignition off.
• Disconnect the negative battery cable.
• Disconnect the rear fog light connector.
• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
• Is the connector normal?
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Yes
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Go to the next step.
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No
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Repair or replace the connector, then go to Step 5.
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3
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INSPECT ELECTRICAL SUPPLY UNIT (ESU) CONNECTOR CONDITION
• Disconnect the electrical supply unit (ESU) connector.
• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
• Is the connector normal?
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Yes
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Go to the next step.
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No
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Repair or replace the connector, then go to Step 5.
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4
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INSPECT REAR FOG LIGHT CIRCUIT FOR SHORT TO GROUND
• Verify that the rear fog light and electrical supply unit (ESU) connectors are disconnected.
• Inspect for continuity between rear fog light terminal A (wiring harness-side) and body ground.
• Is there continuity?
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Yes
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Refer to the wiring diagram and verify whether or not there is a common connector between rear fog light terminal A and electrical supply unit (ESU) terminal 2C.
If there is a common connector:
• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
• Repair or replace the malfunctioning part.
If there is no common connector:
• Repair or replace the wiring harness which has a short to ground.
Go to the next step.
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No
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Go to the next step.
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5
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VERIFY THAT REPAIRS HAVE BEEN COMPLETED
• Always reconnect all disconnected connectors.
• Connect the negative battery cable.
• Clear the DTC for the electrical supply unit (ESU) using the M-MDS.
• Perform the following operation.
• Retrieve the electrical supply unit (ESU) DTCs using the M-MDS.
• Is the same DTC displayed?
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Yes
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Repeat the inspection from Step 1.
• If the malfunction recurs, replace the electrical supply unit (ESU).
Go to the next step.
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No
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Go to the next step.
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6
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VERIFY IF OTHER DTCs DISPLAYED
• Are any other DTCs displayed?
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Yes
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Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
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No
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DTC troubleshooting completed.
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