U0143: Lost Communication With Body Control Module C

What it means

A control module has stopped receiving expected messages from body control module C. Body functions managed by that module may be limited or unavailable.

How it works

Body control module C controls body-related functions and exchanges messages with other vehicle modules. This code sets when expected messages from BCM C are missing; a power or ground fault, damaged network wiring, a failed module, or low system voltage can interrupt that exchange.

Common causes

Most likely first.

1. Body control module C power or ground fault
2. Damaged network wiring or connector
3. Body control module C failure
4. Low system voltage

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Scan every module and save freeze-frame data and communication codes to determine whether BCM C alone is missing or several modules lost contact together.
2. Check battery condition and charging-system operation, since low voltage can make modules drop offline and trigger network faults.
3. Identify the functions associated with BCM C in the vehicle's service information and check which are inoperative, while noting which modules still communicate.
4. Inspect BCM C connectors, power and ground connections, and accessible network wiring for loose pins, corrosion, water entry, or damage.
5. Use the correct wiring diagram to test BCM C power and ground under load and check its network circuit for an open, short, or poor connection against the manufacturer's specification.
6. If wiring and supplies pass, follow the manufacturer's procedure to determine whether BCM C has failed before replacing or programming it.

Common fixes

• Charge or replace a weak battery and repair a charging-system problem if present.
• Clean and secure BCM C connectors or repair corroded or damaged terminals.
• Repair a failed BCM C power or ground connection.
• Repair an open, short, or damaged section of the network wiring.
• Replace and configure BCM C only when testing confirms module failure.

Can I keep driving?

Because this fault can affect multiple modules or disable vehicle functions, check for problems with starting, steering, braking, lighting, and visibility before driving. Do not drive if a safety-critical function is impaired or the vehicle enters limp mode; arrange diagnosis promptly.