Exhaust Aftertreatment Fuel Injector Circuit Low
The P2699 code indicates that the Powertrain Control Module (PCM) has detected a low voltage or resistance condition in the electrical circuit of the exhaust aftertreatment fuel injector. This injector is used in diesel engines to introduce fuel into the exhaust stream for regeneration of the Diesel Particulate Filter (DPF) or to raise exhaust temperature for Selective Catalytic Reduction (SCR) systems. A low circuit condition can result from wiring issues, a faulty injector, or a problem with the PCM itself, potentially leading to incomplete regeneration and increased emissions.
1. Most Common Causes
- Faulty exhaust aftertreatment fuel injector
- Open or shorted wiring in the injector circuit
- Poor electrical connection at the injector or PCM
- Failed PCM (rare)
2. Symptoms You Will Notice
- Illuminated Check Engine Light
- Reduced fuel economy
- Increased exhaust emissions
- Possible DPF regeneration issues or frequent regeneration cycles
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes (e.g., P2697, P2698).
Step 2: Visually inspect the injector wiring and connector for damage, corrosion, or loose pins.
Step 3: Measure resistance of the injector and compare to manufacturer specifications (typically 0.5-2 ohms).
Step 4: Check for voltage at the injector connector with the engine running; should be near battery voltage.
Step 5: If wiring and injector are okay, test the PCM output circuit or consider PCM replacement.
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, causing clogging and potential damage to the exhaust system. You may notice reduced performance and increased emissions.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. The injector itself costs $50-$150, and labor adds $100-$250 depending on the vehicle and shop rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.