What does it mean?
P1375 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: IC Module 24X Reference Circuit High Input .
Symptoms
- MIL on with the code stored
- Hard starting, especially on a cold engine, with long cranking
- Cutting out and stalling at low speed
- Rough idle and misfire at light load
- Occasional tachometer spikes
Likely causes
- Short to battery voltage somewhere in the 24X reference circuit
- Chafed insulation letting the signal wire touch a power feed
- Faulty 24X crank sensor mounted at the front of the engine
- Corroded or pushed-out terminal producing a false high reading
- Water or coolant intrusion into the sensor or module connector
- Ignition control module output stage failure
- PCM internal pull-up circuit fault
How to fix it
- Inspect the 24X sensor connector at the front of the engine, oil and coolant contamination is common there
- Unplug the sensor and measure circuit voltage back to the module: voltage present with the sensor disconnected means a short to power
- Check harness routing near power leads, the alternator and air conditioning wiring for chafe points
- Verify the sensor ground and reference feed at the connector
- Scope the signal and evaluate its amplitude and any dropouts
- Repair the short or replace the 24X sensor and retest before condemning the module
- Confirm the repair with a cold start and a road test