Engine Hot Lamp Output Control Circuit Malfunction
The P0655 code indicates a malfunction in the circuit that controls the engine hot warning lamp. This lamp is typically located on the dashboard and illuminates when the engine coolant temperature exceeds a safe threshold. The Powertrain Control Module (PCM) monitors the circuit for proper voltage and resistance. A fault can be due to a shorted or open circuit, a blown fuse, a faulty lamp bulb, or a defective PCM. This code does not necessarily mean the engine is overheating; it points to an electrical issue with the warning system.
01. Most Common Causes
- Blown fuse in the engine hot lamp circuit
- Faulty engine hot lamp bulb or socket
- Short or open in the wiring or connectors
- Defective PCM (rare)
02. Symptoms You Will Notice
- Engine hot warning lamp stays on continuously
- Engine hot warning lamp does not illuminate when engine is overheating
- Check Engine Light may be on
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for any other related codes.
Step 2: Visually inspect the engine hot lamp bulb and socket for damage or corrosion.
Step 3: Check the fuse for the engine hot lamp circuit and replace if blown.
Step 4: Test the wiring and connectors between the PCM and the lamp for continuity and shorts.
Step 5: If all else is fine, test the PCM output for the lamp circuit; replace PCM if necessary.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive, but you may not receive a warning if the engine actually overheats, which could lead to severe engine damage. It is recommended to diagnose and fix the issue promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts and labor. Most repairs involve replacing a bulb, fuse, or repairing wiring. PCM replacement is rare and more expensive.