P1271: Cylinder #1 Fuel Injector Circuit Open
The P1271 code indicates an open circuit in the fuel injector for cylinder #1, meaning the injector is not receiving power or ground, or the injector coil is internally broken. This prevents fuel delivery to cylinder #1, causing a misfire and potential engine damage if ignored.
1. Symptoms You Will Notice
- Check Engine Light on
- Engine misfire at idle or under load
- Rough running or hesitation
- Decreased fuel economy
2. Most Common Causes
- Internal short circuit in the #6 injector solenoid
- Damaged or chafed wiring causing a short between the high-side and low-side injector circuits
- Faulty high-side driver in the ECU/PCM
- Faulty low-side driver in the ECU/PCM
- Poor connection or corrosion at the #6 injector connector
- Short circuit in the engine harness between the injector circuits
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.
Step 3: Use a multimeter to measure resistance across injector terminals (should be 11-18 ohms).
Step 4: Check for 12V power at injector with key on; if missing, trace circuit back to fuse/relay.
Step 5: Perform a noid light test to confirm PCM injector driver signal.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with a misfire can damage the catalytic converter and cause further engine issues. Have it repaired promptly.
How much does it cost to fix?▼
Typically $100-$300 for injector replacement, plus diagnostic time. Wiring repairs may be less.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.