MIL Control Circuit Malfunction (P0650)
The P0650 code indicates a malfunction in the control circuit of the Malfunction Indicator Lamp (MIL), commonly known as the check engine light. The powertrain control module (PCM) monitors the MIL circuit for proper operation. When the PCM detects an open, short, or excessive resistance in the circuit, it sets this code. This can prevent the MIL from illuminating when a fault is present, potentially hiding other issues.
01. Most Common Causes
- Blown fuse for the MIL circuit
- Faulty MIL bulb or LED
- Damaged wiring or connector in the MIL circuit
- Faulty instrument cluster
- Faulty PCM
02. Symptoms You Will Notice
- Check engine light does not illuminate when key is turned to ON position
- Check engine light stays on constantly or flickers
- Other warning lights may malfunction
- Possible failure to pass emissions testing due to non-functional MIL
03. Step-by-Step Diagnosis
Step 1: Check the MIL fuse in the fuse box; replace if blown.
Step 2: Inspect the MIL bulb or LED; replace if burned out.
Step 3: Visually inspect wiring and connectors for damage, corrosion, or loose connections.
Step 4: Use a multimeter to test continuity and voltage in the MIL circuit.
Step 5: If all else is fine, suspect a faulty instrument cluster or PCM and consult a professional.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, the vehicle is generally safe to drive, but the MIL may not warn you of other serious issues. It is recommended to diagnose and fix the problem promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the cause. Simple fixes like replacing a fuse or bulb are cheaper; wiring repairs or cluster replacement cost more.