Exhaust Aftertreatment Glow Plug Control Circuit Low
The P269D code indicates that the powertrain control module (PCM) has detected a low voltage condition in the control circuit for the exhaust aftertreatment glow plug. This glow plug is used to heat the diesel particulate filter (DPF) or selective catalytic reduction (SCR) system during regeneration or cold starts. A low circuit condition typically means the voltage is below the expected threshold, often due to a short to ground, faulty glow plug, or damaged wiring. This can prevent proper exhaust aftertreatment operation, leading to increased emissions and potential DPF clogging.
01. Most Common Causes
- Short to ground in the glow plug control circuit
- Faulty exhaust aftertreatment glow plug
- Damaged wiring or connector in the glow plug circuit
- Failed glow plug relay or control module
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel efficiency
- Increased exhaust emissions
- Possible DPF regeneration issues
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the glow plug wiring and connectors for damage, corrosion, or loose connections.
Step 3: Measure the resistance of the glow plug; compare to manufacturer specifications.
Step 4: Check the glow plug control circuit for shorts to ground using a multimeter.
Step 5: Test the glow plug relay and control module for proper operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can lead to DPF clogging and increased emissions. Short trips may be possible, but the issue should be addressed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, depending on the cause. Replacing a glow plug or repairing wiring may cost more if parts are needed.