Injector Circuit Malfunction - Cylinder 6
The PCM detected a malfunction in the fuel injector circuit for cylinder 6, indicating either a defective injector or a wiring/electrical problem preventing proper fuel delivery to that cylinder. This causes an imbalance in the fuel mixture and triggers the check engine light.
What You Might Notice
- Engine misfire on cylinder 6
- Rough idle and rough running
- Poor acceleration and reduced power
- Check engine light illuminated
- Possible fuel smell from exhaust
Most Common Causes
- 1
Faulty fuel injector
The injector for cylinder 6 is stuck open, stuck closed, or leaking internally, preventing proper fuel spray pattern and quantity to the cylinder.
- 2
Open wiring in injector circuit
A break or disconnection in the wiring harness between the PCM and the cylinder 6 injector, stopping electrical signal from reaching the injector.
- 3
Short in injector wiring
A short circuit in the wiring harness to the cylinder 6 injector causing the PCM to lose control of the injector or detect an abnormal electrical condition.
- 4
Defective PCM or connection issue
A failing engine control module unable to properly command the injector circuit, or corroded connectors preventing proper electrical communication.
How to Diagnose It
- 1
Check Faulty fuel injector — The injector for cylinder 6 is stuck open, stuck closed, or leaking internally, preventing proper fuel spray pattern and quantity to the cylinder.
- 2
Check Open wiring in injector circuit — A break or disconnection in the wiring harness between the PCM and the cylinder 6 injector, stopping electrical signal from reaching the injector.
- 3
Check Short in injector wiring — A short circuit in the wiring harness to the cylinder 6 injector causing the PCM to lose control of the injector or detect an abnormal electrical condition.
- 4
Check Defective PCM or connection issue — A failing engine control module unable to properly command the injector circuit, or corroded connectors preventing proper electrical communication.
How to Fix It
- 1
Replace fuel injector
Remove and replace the cylinder 6 fuel injector with a new or professionally cleaned remanufactured unit. Inspect the injector seat for damage and clean if necessary.
- 2
Inspect and repair wiring harness
Test the injector wiring circuit with a multimeter for continuity and resistance. Repair any broken wires, corrosion, or loose connections in the harness from the PCM to the injector connector.
- 3
Clean or replace connectors
Disconnect the fuel injector and PCM connectors for cylinder 6 circuit. Clean any corrosion from the connector pins with electrical contact cleaner and a wire brush, or replace corroded connectors.
- 4
Reflash or replace PCM
If wiring and injectors test good, have the PCM flashed with updated firmware or replaced if the module itself is defective and cannot command the injector properly.
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