Cylinder 9 Glow Plug Control Circuit Low
The P069A code indicates that the powertrain control module (PCM) has detected a low voltage condition in the glow plug control circuit for cylinder 9. This circuit supplies power to the glow plug, which aids in cold starts by heating the combustion chamber. A low voltage reading suggests excessive resistance, a short to ground, or a faulty component in the circuit, potentially causing hard starting or misfires in cold weather.
01. Most Common Causes
- Faulty glow plug in cylinder 9
- Open or shorted glow plug wiring or connector
- Failed glow plug control module or relay
- Corroded or loose electrical connections
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Hard starting, especially in cold weather
- Engine misfire or rough idle
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect glow plug wiring and connector at cylinder 9 for damage or corrosion.
Step 3: Measure resistance of glow plug at cylinder 9; compare to spec (typically 0.5-2 ohms).
Step 4: Check voltage at glow plug connector with key on; should be battery voltage.
Step 5: Test glow plug control module/relay output and ground circuits.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It may be safe in warm weather, but in cold conditions the engine may be hard to start or run poorly. It's best to repair promptly to avoid starting issues.
How much does it cost to fix?▼
Typically $50-$150 for a single glow plug replacement, plus diagnostic time. Costs vary by vehicle and labor rates.