Engine Control Module (ECM) Power Supply Voltage
The power supply voltage to the ECM is out of range.
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 computer that controls the engine isn't getting enough power, which can mess up how the engine runs.
What the computer is actually seeing
The ECM expects a power supply voltage between 9 and 16 volts during operation. If it sees below 9 volts or above 16 volts, it triggers a fault code.
What a healthy reading looks like
Power supply voltage should be between 9.0 and 16.0 volts.
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. Start with a visual inspection of the ECM wiring and connectors for corrosion or damage.
- 22. Check battery voltage; it should be around 12.6 volts when off and 13.7 to 14.7 volts when running.
- 33. With the engine running, confirm that the power to the ECM is within 9-16 volts using a multimeter.
- 4 - If voltage is out of range, go to step 4.
- 54. Inspect the connections at the battery and ignition switch for loose or damaged wires. Repair as needed.
- 65. If wiring is good and power supply is within range but fault persists, consider replacing the ECM.
Common causes
- Weak battery
- Corroded or damaged wiring harness
- Faulty ECM
- Loose or dirty connectors
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I drive the vehicle with this code?
It's best to fix this soon; drivability can be affected.
Will this code come back after resetting?
If the underlying issue isn't fixed, yes, it will likely return.
Why does this code show up with other codes?
Many voltage issues can affect multiple systems, causing related fault codes.
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