Lost Communication With Body Control Module B
What it means
U0142 means the vehicle has lost communication with body control module "B" — a computer that runs body electronics such as lighting, locks, windows, and wipers. When it goes offline, those convenience features stop working reliably and warning messages appear. The car usually still drives, though some designs tie the BCM into the immobilizer. The cause is normally a wiring, connector, power/ground, or bus fault at the module.
Can I keep driving? Usually yes, but expect body/comfort features (lighting, locks, windows) to misbehave; on some vehicles the BCM ties into the immobilizer, so a hard fault can prevent starting.
Common symptoms
What you'll notice
- Multiple warning lights or messages at once
- Body/comfort features fail (exterior/interior lights, locks, windows, wipers)
- Interior electronics behave erratically
- Scan tool can't reach body control module B
Common causes
Most likely first
- Power or ground fault to the body control moduleLikely
- Damaged or corroded connector or wiring at the moduleCommon
- Failed body control moduleCommon
- CAN bus wiring fault to the moduleLess often
How to diagnose & fix
Work through it in order
- Scan all modules for related U-codes and note which features are lost.
- Check the module's power and grounds.
- Inspect connectors and wiring for corrosion or damage.
- Verify bus communication to the module.
- Replace the BCM only after wiring, power, and ground check good; program it if required.
FAQ
Quick answers
Is it safe to drive with U0142?+
Can I just clear U0142?+
Related codes
Often seen with U0142
Read & clear U0142 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.