P0655
Engine Hot Lamp Output Control Circuit
ECM output / warning lamp
Generic OBD-II
High
What it means
P0655 means the ECM detected a fault in the output circuit that drives the engine-hot (overheat) warning lamp. The engine runs normally, but the warning that tells you it is overheating may not work correctly. It is usually a bulb, wiring, or connection fault, with the ECM being the least likely cause.
High
Can I keep driving? Driveable, but the engine-hot warning lamp may not work — watch the temperature gauge yourself so you don't miss an overheat.
Common symptoms
What you'll notice
- Check-engine light on
- Engine-hot / overheat warning lamp not working or behaving abnormally
- Warning lamp stuck on or flashing when it shouldn't
Common causes
Most likely first
- Failed engine-hot indicator bulb/LED or its circuitLikely
- Open, shorted, or corroded wiring in the lamp output circuitCommon
- Poor connection at the lamp or ECM connectorCommon
- Faulty engine control module (ECM), least likelyLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the lamp output circuit is at fault.
- Check the engine-hot indicator bulb/LED and its socket.
- Inspect the lamp output wiring for opens, shorts, or corrosion.
- Verify the ECM can drive the lamp circuit; repair wiring or replace the bulb as needed.
- Only consider the ECM after the bulb and wiring check out.
FAQ
Quick answers
Is it safe to drive with P0655?+
The engine itself is unaffected, but the overheat warning lamp may not alert you. Keep an eye on the temperature gauge and fix the circuit soon.
Can I just clear P0655?+
It will return until the lamp, wiring, or driver circuit is repaired. Clearing it won't restore the warning function.
Related codes
Often seen with P0655
Read & clear P0655 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX