Exhaust Aftertreatment Fuel Injector Control Circuit High
The P20CE code indicates that the powertrain control module (PCM) has detected a voltage higher than expected 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 condition typically points to a short to power, a faulty injector, or a wiring issue.
01. Most Common Causes
- Short to battery voltage in the injector control circuit
- Faulty exhaust aftertreatment fuel injector
- Damaged wiring or connector
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel economy
- DPF regeneration issues
- Possible engine performance problems
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the injector wiring and connector for damage, corrosion, or shorts.
Step 3: Test the injector resistance with a multimeter; compare to manufacturer specs.
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.
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 incomplete DPF regeneration, increased emissions, and potential damage to the aftertreatment system.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, depending on the cause. Replacing the injector can cost $200-$350, while wiring repairs are usually less.