Fuel Cap Lamp Control Circuit Malfunction
The P0624 code indicates a fault in the fuel cap lamp control circuit. This circuit is responsible for illuminating the fuel cap warning light on the dashboard when the fuel cap is loose or missing. The issue may be caused by a faulty fuel cap sensor, a short or open in the wiring, a defective instrument cluster, or a problem with the powertrain control module (PCM).
01. Most Common Causes
- Faulty fuel cap sensor
- Open or short in the fuel cap lamp control circuit wiring
- Defective instrument cluster
- Failed powertrain control module (PCM)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Fuel cap warning light on the dashboard does not illuminate when the cap is loose or missing
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the P0624 code and check for any related codes.
Step 2: Visually inspect the fuel cap and tighten it if loose. Clear the code and see if it returns.
Step 3: Test the fuel cap sensor and its wiring for continuity and shorts using a multimeter.
Step 4: Check the instrument cluster for proper operation of the fuel cap warning light.
Step 5: If all else fails, test the PCM for proper output to the fuel cap lamp circuit.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but you may not be alerted if the fuel cap is loose, which can cause fuel evaporation and increased emissions.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, depending on the root cause. Replacing a sensor or repairing wiring is usually on the lower end, while instrument cluster or PCM replacement can be more expensive.