Engine Control Module (ECM) Power Supply Circuit Low
Indicates low voltage on the ECM power supply circuit.
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 Engine Control Module isn't getting enough voltage to operate properly, usually below 8 volts even when the vehicle is on.
What the computer is actually seeing
The ECM monitors its input voltage from the power supply circuit. If this voltage drops below the expected level, it triggers a fault code.
What a healthy reading looks like
Expected voltage is typically around 12-14 volts when the engine is running.
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.
- 1Check battery voltage; should be between 12-14 volts. If lower, charge or replace battery.
- 2Inspect all related wiring and connectors for damage or corrosion. Look for any loose connections.
- 3Test the voltage at the ECM connector. Should be at least 8 volts with the ignition on. If low, trace the circuit back to find the issue.
- 4Check for shorts to ground in the power supply circuit using a multimeter. Repair any identified shorts.
Common causes
- Bad wiring or connectors in the ECM power circuit
- Weak battery or poor battery connections
- Faulty ECM
- Short circuit to ground in power circuit
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive. Low power can lead to erratic engine behavior.
Will this code come back after being cleared?
Yes, if the underlying issue isn't fixed, it will return.
Could this be related to other codes?
Yes, it often pairs with other power circuit-related codes.
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