P1627
OBD-II Diagnostic Code
Severity: CriticalWhat it means
P1627 means the ECM (Engine Control Module) has detected an internal malfunction.
This is a self-diagnostic code indicating the ECM itself may be failing.
Clear the code and monitor — if it returns, the ECM may need replacement or reprogramming.
Affected Models
- Honda
- Nissan
- GM vehicles
- Various manufacturers
Common Causes
- ECM internal circuit failure
- ECM software corruption
- Power supply voltage irregularity to the ECM
- Water intrusion damaging the ECM
- ECM connector corrosion
How to Fix It
-
Clear the code and see if it returns.
Sometimes power glitches cause one-time internal errors.
If the code does not return, it was likely transient. -
Check the ECM power and ground connections.
A poor ground or unstable power supply can cause internal ECM errors.
Clean and tighten all ECM connector pins. -
Inspect the ECM for water damage.
On some vehicles, the ECM is mounted where water can reach it.
Look for corrosion on the ECM case or connectors.
Frequently Asked Questions
How much does an ECM replacement cost?
A new ECM costs $500-$1500.
Remanufactured units cost $300-$800.
Programming to the vehicle adds $100-$200.
Can a weak battery cause P1627?
Yes.
A dying battery or loose battery connection causes voltage fluctuations that can trigger internal ECM errors.