Invalid Data Received from Body Control Module 'A'
The Engine Control Module (ECM) detected invalid data from the body control module.
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What it means (plain English)
The car's engine computer is not getting proper info from the body control module, which manages things like lights and door locks.
What the computer is actually seeing
The ECM expects to receive a specific data signal from the body control module that indicates its operational status; instead, it receives an invalid or corrupted signal.
What a healthy reading looks like
The expected data signal should be within nominal voltage ranges from 0.5V to 4.5V at specified intervals based on communication protocols (typically CAN bus).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check all related wiring and connectors for damage or corrosion. Repair as necessary.
- 22. Verify that the body control module is receiving power and ground using a multimeter (standard voltage should be 12V with the ignition on). If not, repair the power or ground issue.
- 33. Monitor the data transmission on the CAN bus between the ECM and the body control module. Look for abnormal patterns or missing signals.
- 44. If wiring and power are okay, consider swapping out the body control module with a known good unit to see if the fault clears.
Common causes
- Faulty body control module
- Wiring issues between the ECM and the body control module
- Poor connections or corroded terminals
- Intermittent faults in the CAN bus wiring
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive, but some features may be inoperative. Keep an eye on dashboard lights and unusual behavior.
Will this problem return after fixing?
If the root cause is properly addressed, it shouldn't return. Ensure all wiring and connections are solid.
Why does this code pair with U0420?
Both codes indicate issues with data communication, usually stemming from problems in the same financial line of systems.
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