Database Rejection Message
The engine control module (ECM) received a rejected database message from the connected device.
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 ECM is trying to communicate with another part of the system but is getting a 'no go' signal, meaning a request was denied or there was a problem understanding the data.
What the computer is actually seeing
The ECM detects a message was sent from another module or system component that wasn't accepted, typically involving issues like incorrect configurations or incompatible parameters.
What a healthy reading looks like
Typically, you'd see real-time data exchange about engine parameters, with proper acknowledgments (ACK) in response to requests, indicating successful communications.
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 for recent changes or updates to the ECM or connected devices. If updates were made, verify compatibility.
- 22. Inspect all wiring and connectors from ECM to the device. Look for corrosion, breaks, or loose connections. Fix as needed.
- 33. Using a diagnostic scanner, check for related fault codes — if other database error codes are present, investigate those first.
- 44. If all checks clear, look at the device that is communicating with the ECM. Check for functionality and proper installation. Swap with a known good unit if available.
- 55. Clear fault codes and perform a communication test again. If SPN 5602 returns, further investigation into the device or ECM configuration may be necessary.
Common causes
- Faulty wiring or connectors between the ECM and the device
- Incompatible software or firmware versions between systems
- Failure in the device sending the database message
- Corrupt data being reported by another module
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Can I drive the vehicle with this code?
Yes, but it's advisable to address the issue soon as it may lead to larger communication problems.
Will this code come back after clearing it?
If the underlying issue isn't resolved, it's likely to return.
Why does this code appear alongside other codes?
It often indicates a broader communication issue which could be affecting multiple systems.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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