Exhaust Aftertreatment Fuel Injector Control Circuit High
The P20CE code indicates that the powertrain control module (PCM) has detected a high voltage condition in the control 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 high voltage signal suggests a short to power, open circuit, or faulty injector, which can prevent proper regeneration and lead to increased emissions and potential DPF clogging.
1. Most Common Causes
- Short to battery voltage in the injector control/signal wire
- Post-treatment injector 'A' internal failure (coil shorted to positive)
- Injector connector damaged, corroded, or with pins making contact
- Engine Control Module (ECM) with faulty output driver
- Wiring chafed or pinched against high-voltage components
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Increased exhaust emissions
- Possible DPF regeneration issues
- Engine may enter limp mode
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the injector wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the injector resistance with a multimeter; compare to manufacturer specifications.
Step 4: Check for voltage at the injector connector with key on; should be battery voltage on one pin and ground on the other.
Step 5: If wiring and injector are okay, test the PCM output circuit for shorts or opens.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with this code, as it can lead to DPF clogging and reduced engine performance. Short trips may be okay, but the issue should be diagnosed promptly.
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.