PRE-RELEASE
DTC B3885 or B3886
| DTC B3885 or B3886 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| DTC Descriptors |
DTC B3885 02
Trailer Left Tail Lamp Circuit Short to Ground
DTC B3885 04
Trailer Left Tail Lamp Circuit Open
DTC B3886 02
Trailer Right Tail Lamp Circuit Short to Ground
DTC B3886 04
Trailer Right Tail Lamp Circuit Open
| Diagnostic Fault Information |
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
| Trailer Left Tail Lamp Control | B3885 02 | B3885 04 | - | - |
| Trailer Right Tail Lamp Control | B3886 02 | B3886 04 | - | - |
| Circuit/System Description |
The trailer brake control module will receive a serial data message from the body control module (BCM) indicating that the vehicle park lamps have been activated. The trailer brake control module will then apply system voltage to the trailer tail lamps through their respective voltage supply circuits.
| Conditions for Running the DTC |
When the parking lamps are turned on.
| Conditions for Setting the DTC |
B3885 02 or B3886 02
The trailer brake control module detects a short to ground on the appropriate tail lamp control circuit.B3885 04 or B3886 04
The trailer brake control module detects an open/high resistance in the appropriate tail lamp control circuit.| Action Taken When the DTC Sets |
The appropriate trailer tail lamp will be inoperative.
| Conditions for Clearing the DTC |
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The DTC will be current for as long as the fault is present.
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When the fault is no longer present, the DTC will be a history DTC.
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A history DTC will clear after 40 ignition cycles.
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| Reference Information |
Schematic Reference
Trailer Connector/Provision Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
Ignition ON, observe the function of the left trailer tail lamp and the right trailer tail lamp while commanding the Left Trailer Tail Lamp and the Right Trailer Tail Lamp ON and OFF with a scan tool. The left trailer tail lamp and the right trailer tail lamp should turn ON and OFF while changing between the commanded states.
| Circuit/System Testing |
| 1. |
Ignition OFF, disconnect the X1 harness connector at the K68 trailer lighting control module.
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| 2. |
Test for infinite resistance between the control circuit terminal listed below and ground:
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Right trailer park lamp control terminal 16
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Left trailer park lamp control terminal 4
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If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the X88 trailer connector.
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| 4. |
Test for less than 1 Ω between the control circuit terminals listed below:
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Control terminal 16 at the K68 trailer lighting control module and control terminal 5 at the X88 trailer connector.
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Control terminal 4 at the K68 trailer lighting control module and control terminal 7 at the X88 trailer connector.
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If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the X88 trailer connector.
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| 6. |
If all the circuits test normal, replace the K68 trailer lighting control module.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for trailer brake control module replacement, programming and setup
