Cylinder 5 Injector Circuit High

Possible causes

• CommonFailed injector - open or shorted winding
• CommonCorroded or damaged connector at the injector
• CommonChafed or heat-damaged wiring in the injector harness
• PossibleBlown fuse or failed relay on the injector supply
• PossibleOil or fuel in the connector from a leaking seal
• RareFailed control module driver

What you might notice

• Misfire - the engine shaking, especially at idle
• Loss of power and hesitation
• Hard starting or no start
• Smell of unburnt fuel
• Check engine light on, or flashing

What to check, in order

1. Disconnect the cylinder 5 injector and check whether the high reading persists at the harness. If it does, the fault is in the wiring rather than the injector.
2. Read all codes. A misfire code for the same cylinder alongside this one confirms which cylinder is not firing.
3. Measure the injector winding resistance and compare it with a known-good injector on the same engine. Comparing against its neighbours is often more useful than a specification.
4. Swap the connector - not the injector - with a neighbouring cylinder and see whether the fault follows. If it does, the fault is in the injector; if it stays, it is in the wiring.
5. Inspect the connector for corrosion, and for oil or fuel that has crept in through a failed seal.
6. Check the injector harness for chafe and heat damage. It sits directly on top of a hot engine and gets disturbed at every service.