01 Decoding Transmission Types: Manual, Automatic, CVT, and DCT • 02 Your ultimate checklist for buying a used car with confiden… • 03 P0072, P0073, and P0074: Ambient Air Temperature Sensor Cir… • 04 Milling Machine Basics: A Complete Guide for Beginners • 05 Mastering Diesel Injector Nozzles: Function, Control, and M… • 06 Avoid These Brake Pads If You Drive in Rainy or Coastal Reg… • 07 Car Security Systems: What They Are and How to Install Them • 08 P0037 H02S heater control circuit low (Bank 1 sensor 2) • 09 From Slight Pause to Complete Failure: Understanding Transm… • 10 Car Warranty Secrets: What Dealers Don't Want You to Know •

DTC codes / U01xx · Lost communication with a control module / U0141

U0141Lost Communication With Body Control Module 'A'

U0141 is a generic communication fault indicating that the engine control module (ECM) or another primary module has lost the controller area network (CAN) signal from the body control module 'A' (BCM-A). The computer detected that expected periodic messages from the BCM-A stopped arriving over the communication bus, which can disable functions like power windows, lighting, and security.

SystemNetwork
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaLost communication with a control module

Symptoms you may notice

  • Multiple warning lights illuminated, including the check engine light, airbag, and ABS lights
  • Power windows, door locks, or interior lighting may stop working or behave erratically
  • The engine may crank but not start, or start and stall immediately
  • The security indicator may flash or the vehicle may fail to recognize the key fob
  • Often no symptoms besides the warning light if the fault is intermittent
  • Other electronic features like the radio or climate control may default to a safe mode

Common causes, most likely first

  1. A weak or failing 12-volt battery or poor battery terminal connections
  2. Corroded, loose, or damaged wiring at the BCM-A connector or along the CAN bus
  3. A faulty body control module 'A' itself, often due to water intrusion or internal failure
  4. Blown fuses that supply power or ground to the BCM-A
  5. A shorted or open CAN bus wire between the BCM-A and other modules
  6. A failed ground connection for the BCM-A or the module that reported the code
  7. Aftermarket accessories improperly tapped into the BCM wiring

How to diagnose and fix it

  1. Perform a battery and charging system test, including load testing and checking terminal cleanliness and tightness
  2. Check all fuses related to the BCM-A and the communication bus, and verify power and ground at the BCM-A connector
  3. Inspect the BCM-A connectors and wiring for corrosion, water damage, or loose pins, and repair as needed
  4. Use a scan tool to check for communication with the BCM-A and perform a network integrity test to identify which modules are offline
  5. Measure CAN bus resistance and voltage to rule out a short or open circuit, then trace and repair any damaged wiring
  6. If all wiring and power supplies are good, substitute a known-good BCM-A or reprogram the existing module according to manufacturer procedures
  7. Clear the code and perform a road test to verify communication is restored and no related codes return

Before you replace the body control module

  • A weak battery is the most common cause of U0141 on modern vehicles, so always load test the battery before condemning the BCM.
  • Water intrusion into the passenger compartment or trunk can corrode BCM connectors and cause intermittent communication loss that mimics a failed module.
  • The code may be set by a different module than the one reporting it, so check all modules for communication errors to pinpoint the true source.
  • Aftermarket alarms or remote starters tapped into the CAN bus often disturb BCM communication and set U0141 without any obvious wiring fault.
  • Replacing the BCM usually requires programming and immobilizer relearn, so a used module from another vehicle will not work without proper adaptation.

Can I keep driving with U0141?

If the vehicle starts and runs normally, you can drive it to a repair shop, but avoid relying on power windows, locks, or security features. If the engine cranks but does not start or stalls, do not drive and have the vehicle towed to prevent safety risks.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage