What does it mean?
P1238 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 2 Fuel Injection Circuit Open Circuit .
Symptoms
- Dead cylinder 2 with a hard misfire and a flashing check engine lamp
- Severe vibration at idle and a stumbling, uneven engine
- Strong loss of power, especially pulling away and on hills
- Fuel smell and possible catalytic converter damage over time
- Engine may still start but runs badly from the moment it fires
Likely causes
- Wire broken inside the insulation, often at a flex point or where a previous repair was made
- Terminal backed out of the injector connector or a connector left unlatched after service
- Injector coil failed open
- Green corrosion in the connector destroying contact
- Loss of the supply feed to that injector from a blown fuse or an open splice
- Open circuit inside the control module output
How to fix it
- Compare the codes; several open injector codes together suggest a common supply problem
- Verify supply voltage at the injector connector with the ignition on and check the relevant fuse
- Inspect the connector for a pushed-out or bent terminal and for corrosion
- Measure the injector resistance and compare with the other cylinders
- Test continuity of the control wire back to the module connector and flex the loom while measuring
- Confirm the module is pulsing the circuit with a noid light
- Repair the harness or fit a new injector according to the findings, then clear the codes and road test
- Check the module driver only when the circuit and injector both test correct