Lost Communication With Body Control Module
What does U0140 mean?
The U0140 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Body Control Module. This is a moderate severity code.
Common Symptoms
- Multiple warning lights on dashboard
- Interior lights malfunction
- Power windows or locks inoperative
- Wipers or turn signals not working
- Key fob does not work
Probable Causes (Ranked by Likelihood)
- Failed body control module (BCM) Very High
- CAN bus wiring fault to BCM High
- BCM connector water damage Moderate
- BCM power supply loss Moderate
Step-by-Step Diagnostic Procedure
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Check BCM power and ground circuits
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Inspect BCM connector for water damage -- BCM is often near the windshield cowl where water leaks occur
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Verify CAN bus wiring to BCM
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Check for water leak into the BCM area
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Replace BCM if communication lost -- requires programming and configuration
Frequently Asked Questions
Can I drive with code U0140?
Drive short distances only. Lost communication codes indicate a module has stopped communicating on the vehicle network. The affected system may not function correctly.
What causes U0140?
The most common cause is a failed module or a wiring issue in the CAN bus network. Failed body control module (BCM) is the most likely cause. Power supply, ground, and connector issues should be checked before replacing any module.
Is U0140 expensive to fix?
Repair costs range from $200 - $1000 (parts and labor). Wiring repairs are on the lower end, while module replacement is on the higher end. The module may also need to be programmed after replacement.