Brake System Control Module Message Fault
There's an issue with the communication between the brake system control module and the engine control module.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The brake system is trying to send messages to the engine control, but it isn't getting through, which means communication problems can affect how the brakes work.
What the computer is actually seeing
The brake system module fails to receive or send proper messages within a specified time frame (usually around 20 milliseconds).
What a healthy reading looks like
Messages between the brake control module and engine control module should be consistent with expected voltages of around 5V for signals; anything lower may indicate a failure or poor connection.
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. Inspect the wiring and connectors between the brake system control module and the engine control module for damage or corrosion. Clean or repair any issues found.
- 22. Check battery voltage; it should be a minimum of 12.4V to ensure proper module operation. If low, charge the battery or check for parasitic draw.
- 33. Use a scan tool to check for additional codes. If other brake-related codes are present, resolve those issues first. If C0890 appears with no other codes, proceed to step 4.
- 44. Check for software updates for both the brake control module and the ECU. Update if necessary to the latest manufacturer specifications.
- 55. If all checks are clear, you may need to replace the brake system control module.
Common causes
- Damaged wiring or connectors between brake control module and ECU
- Faulty brake system control module
- Software issues in the ECM or brake control module
- Battery voltage below 9V causing communication issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; it's best to fix it soon to ensure reliable braking performance.
Will this code come back after clearing it?
If the underlying issue isn't resolved, it will likely return after clearing.
Does this code pair with other codes?
Yes, it's commonly seen with other brake system fault codes that indicate different issues.
Working a real vehicle right now?
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