Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test C : U0142:87: Notes
Normal Operation and Fault Conditions
The Auxiliary Lighting Control Module (ALCM) will show as the BCMB on the scan tool. REFER to: Communications Network - System Operation and Component Description .
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U0142:87 | Lost Communication With Body Control Module "B": Missing Message | A continuous memory DTC that sets in the BCM if data messages from the BCMB through the GWM are missing. |
Possible Sources
- Communication network concern
- Battery voltage concern
- GWM concern
- Auxiliary Lighting Control Module (ALCM) (BCMB)
- BCM
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.