P0655: The engine computer found a fault in the circuit that drives the engine-hot warning lamp
Engine hot lamp output control circuit malfunction
Severity: Severity not verified — if the car runs badly, have it inspected
The sources define the code and list likely causes but say nothing about how urgent it is, so urgency is not verified. A dead hot lamp also means you lose a warning, so watch the temperature gauge.
P0655 in short
P0655 means the engine computer found a fault in the circuit that switches the engine-hot warning lamp. TroubleCodes.net lists the wiring, the lamp itself and the computer as the likely causes. The sources give no urgency, so watch the temperature gauge until it is checked.
The engine computer switches the engine-hot warning lamp on and off. If it sees a problem in that output circuit, it stores P0655.
TroubleCodes.net lists wiring, the engine hot lamp and the engine control module as the probable causes. It does not give a symptom list or a ranking for this code.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Open or shorted wiring to the engine hot lamp
Common general cause- Why it ranks here
- TroubleCodes.net lists wiring first for this circuit code.
- What would change this
- Rises if a visual and electrical check finds a fault here. Falls if it checks out.
Cause 2: Faulty engine hot lamp or its cluster
Common general cause- Why it ranks here
- The lamp is the load on the circuit and is named as a probable cause.
- What would change this
- Rises if a visual and electrical check finds a fault here. Falls if it checks out.
Cause 3: Engine computer output fault
Common general cause- Why it ranks here
- TroubleCodes.net names the engine control module; it ranks last because computer faults are rarer than wiring faults.
- What would change this
- Rises if a visual and electrical check finds a fault here. Falls if it checks out.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Look at the lamp circuit wiring and connectors between the instrument cluster and the engine computer for damage, corrosion or loose pins.
IfDamaged or corroded wiring or a loose connector
It meansRepair the wiring or connector.
IfWiring looks fine
It meansHave the lamp circuit tested.
Step 2: Have a shop test the lamp output circuit for continuity and shorts and check the cluster lamp.
Warning:Probing connectors on the engine computer can short pins and damage the computer; disconnect the battery first and use back-probe tools.
IfCircuit is open or shorted
It meansWiring fault.
IfCircuit is good but the lamp does not respond
It meansLamp or cluster fault.
IfCircuit and lamp are good
It meansComputer output is suspect.
Symptoms
- Check engine light on with the code stored
- Engine hot warning lamp that stays on or never lights
How to fix
Step 1: Visually check the wiring and connectors at the instrument cluster for damage or looseness with the ignition off.
Parts and cost context
- Engine control module (ECM / PCM):Computer faults are the least common cause here. Test the wiring and lamp first. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
We don't have reviewed vehicle-specific evidence for P0655 yet. The causes and tests above apply across vehicles.
Related codes
P0655 questions
What does P0655 mean?
The engine computer found a fault in the circuit that drives the engine-hot warning lamp.
Sources and review
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error