U0141: Lost Communication With Body Control Module A

What it means

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

At a glance

• Usually lights the warning light of the system that lost communication

How it works

Body control module A manages body-related functions and sends status messages over the vehicle network. This code sets when another module does not receive the expected messages from BCM A, which can happen if the module loses power or ground, the network connection is disrupted, or system voltage is low.

Common causes

Most likely first.

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

Symptoms

• Body or electrical warning
• Some body functions may be unavailable
• Other communication codes

How to diagnose it

1. Scan all modules and review freeze-frame data to see when communication with BCM A was lost and whether low-voltage or other network codes were recorded at the same time.
2. Check battery condition and charging-system operation, since low system voltage can interrupt BCM A communication and create several communication codes.
3. Check which modules can communicate with BCM A and test its body functions to help determine whether the fault is limited to this module or affects a wider network.
4. Inspect BCM A connectors, power and ground connections, and nearby network wiring for looseness, corrosion, water entry, or damage.
5. With the correct wiring information, test BCM A power and ground under load and check the network circuit for an open, short, or poor connection against the manufacturer's specification.
6. If power, ground, and network wiring are sound, follow the manufacturer's diagnostic procedure to assess BCM A before considering module replacement.

Common fixes

• Charge or replace a weak battery and repair a charging-system fault if found.
• Reconnect or clean a loose or corroded BCM A connector and repair damaged wiring.
• Repair BCM A power or ground connections that fail testing.
• Repair an open, short, or poor connection in the relevant network wiring.
• Replace or reprogram BCM A only if diagnosis confirms it is faulty and the vehicle requires programming.

Can I keep driving?

If the vehicle drives normally and only nonessential body features are affected, a short, cautious trip may be possible, but do not rely on affected functions such as exterior lighting or door locks. Stop if essential lighting, visibility, starting, or other safety-related functions are impaired.