Exhaust Aftertreatment Glow Plug Circuit High
The P26A2 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the exhaust aftertreatment glow plug circuit. This circuit is used to heat the diesel particulate filter (DPF) or selective catalytic reduction (SCR) system to aid in regeneration and reduce emissions. A high voltage reading suggests a short to power, faulty glow plug, or wiring issue.
1. Most Common Causes
- Short to power in the glow plug circuit
- Faulty exhaust aftertreatment glow plug
- Damaged wiring or connector
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel efficiency
- Increased exhaust emissions
- Possible DPF regeneration issues
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Visually inspect the glow plug wiring and connector for damage or corrosion.
Step 3: Measure voltage at the glow plug connector with key on; should be battery voltage. If high, check for short to power.
Step 4: Test the glow plug resistance; compare to specifications. Replace if out of range.
Step 5: Clear code and test drive to verify repair.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can lead to incomplete DPF regeneration and potential damage to the exhaust system.
How much does it cost to fix?▼
Typically between $50 and $150 for parts and labor, depending on the cause and vehicle model.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.