Cylinder 10 Glow Plug Control Circuit High
The P069D code indicates that the powertrain control module (PCM) has detected a high voltage condition in the glow plug control circuit for cylinder 10. This circuit is responsible for energizing the glow plug to aid cold starts in diesel engines. A high voltage reading suggests a short to power, a faulty glow plug, or a problem with the glow plug control module. This can lead to extended cranking, rough idle, and increased emissions.
1. Most Common Causes
- Faulty glow plug in cylinder 10 or incorrect resistance
- Glow plug control circuit shorted to battery voltage (B+)
- Damaged, corroded, or loose connector or terminal in the glow plug circuit
- Internal failure of the glow plug control module
- Internal ECM failure (less common)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Hard starting, especially in cold weather
- Rough idle or misfire on cylinder 10
- Excessive smoke from exhaust during startup
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the glow plug wiring and connector at cylinder 10 for damage or corrosion.
Step 3: Measure resistance of glow plug at cylinder 10; compare to spec (typically 0.5-2 ohms).
Step 4: Check for voltage at the glow plug connector with key on; should be battery voltage during glow cycle.
Step 5: Test the glow plug control module output for cylinder 10 using a multimeter or scan tool.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause hard starting, poor engine performance, and potential damage to the glow plug system. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether it's a simple wiring repair or glow plug replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.