Cylinder 11 Injector Circuit Low
The P0291 code indicates that the powertrain control module (PCM) has detected a low voltage or resistance condition in the electrical circuit for the fuel injector on cylinder 11. This typically means the injector circuit is drawing less current than expected, which can be caused by a faulty injector, wiring issues, or a problem with the PCM driver. The injector may not open properly, leading to a lean condition or misfire.
1. Most Common Causes
- Faulty fuel injector on cylinder 11
- Open or shorted wiring in injector circuit
- Poor electrical connection at injector or PCM
- Failed PCM driver for cylinder 11 injector
2. Symptoms You Will Notice
- Engine misfire on cylinder 11
- Rough idle or hesitation
- Check Engine Light illuminated
- Possible fuel odor or poor fuel economy
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect injector connector and wiring for damage or corrosion.
Step 3: Measure resistance of cylinder 11 injector (typically 12-16 ohms).
Step 4: Check for voltage and ground at injector connector with key on.
Step 5: Perform a injector balance test or swap injector to see if code follows.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause misfire, catalytic converter damage, and poor performance. Immediate diagnosis is advised.
How much does it cost to fix?▼
Repair costs vary: injector replacement $150-$400, wiring repair $100-$300, PCM replacement $500-$1000. Diagnosis fee is typically $100-$150.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.