Cylinder 5 Glow Plug Incorrect
The P06C9 code indicates that the Engine Control Module (ECM) has detected an incorrect glow plug in cylinder 5, meaning the glow plug's resistance or electrical characteristics do not match the expected values for that cylinder. This can be due to a faulty glow plug, wiring issues, or an ECM programming error. The glow plug system is critical for cold starts in diesel engines, and an incorrect plug can cause misfires, rough idle, and increased emissions.
1. Most Common Causes
- Faulty glow plug in cylinder 5
- Wiring or connector damage to cylinder 5 glow plug
- ECM software or programming error
- Incorrect glow plug installed during previous repair
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Hard starting, especially in cold weather
- Rough idle or misfire on cylinder 5
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan the ECM for codes and record freeze frame data.
Step 2: Visually inspect the glow plug wiring and connector for cylinder 5 for damage or corrosion.
Step 3: Measure the resistance of the cylinder 5 glow plug and compare to specifications (typically 0.5-2 ohms).
Step 4: If resistance is out of range, replace the glow plug.
Step 5: If wiring and plug are okay, check for ECM updates or reprogramming.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code, especially in cold weather, as it can cause hard starting, misfires, and potential damage to the engine or catalytic converter.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a single glow plug replacement, including parts and labor. If wiring or ECM issues are found, costs may be higher.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.