U0100
Lost Communication With ECM/PCM A
U0100 is an OBD-II diagnostic trouble code meaning: Lost Communication With ECM/PCM A. Common causes: open or short circuit in the can bus, ecm/pcm power supply problems. Estimated repair cost: $56–333.
Symptoms
- The Check Engine light comes on
- Loss of engine power
- The car goes into emergency mode
- Unstable engine operation
- Errors in other vehicle systems
Causes
- Open or short circuit in the CAN bus
- ECM/PCM power supply problems
- Malfunction of the ECM/PCM module itself
- Damage to wiring or connectors
- Module grounding problems
How to Fix
- Check ECM/PCM related fuses
- Inspect module connectors and wiring
- Check ECM/PCM supply voltage parameters
- Scan the CAN bus for errors
- Replace ECM/PCM if necessary
Related codes
Error U0100 by Vehicle Brand
FAQ
What does the U0100 code mean?
U0100 is an OBD-II diagnostic trouble code that indicates: Lost Communication With ECM/PCM A
What causes a U0100 error code?
The most common causes of U0100 include: Open or short circuit in the CAN bus; ECM/PCM power supply problems; Malfunction of the ECM/PCM module itself; Damage to wiring or connectors.
How do I fix a U0100 diagnostic trouble code?
To fix U0100: Check ECM/PCM related fuses. Inspect module connectors and wiring. Check ECM/PCM supply voltage parameters. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U0100?
Do not drive — repair immediately
How much does it cost to fix U0100?
The estimated repair cost for U0100 is $56–333. Actual cost depends on your vehicle, location, and labor rates.
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