Diagnostic trouble code P1375 is a manufacturer-specific powertrain fault code. Because it is manufacturer-specific, its exact definition depends entirely on the vehicle make, model, and application.
Exact vehicle application must be verified before diagnosis. The code identifies a detected condition in a specific subsystem, but further testing is required to identify the root cause.
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Key Takeaways
- P1375 is a manufacturer-specific code, meaning its definition varies between automakers like General Motors and Honda.
- On GM applications, it indicates an Ignition Control (IC) 24X Reference Circuit High Voltage fault.
- On Honda and Acura applications, it points to an ignition coil cylinder 5 early activation fault.
- Diagnosis requires verifying the exact factory definition and testing the relevant ignition or sensor circuits.
- Repairs depend on the confirmed root cause and may involve replacing sensors, coils, or fixing wiring.
P1375 Code Description and Implications
Because P1375 is manufacturer-specific, there is no single universal definition. This error code identifies a detected condition, but the exact monitored system depends on the vehicle make and model.
Some General Motors applications: P1375 indicates an “IC 24X Reference Circuit High Voltage” fault. The powertrain control module detects an abnormally high voltage signal on the 24X reference circuit from the ignition control module or crankshaft position sensor.
Certain Honda and Acura applications: P1375 indicates an “Ignition Coil – Cylinder 5 – Early Activation Fault,” meaning the engine control module detects that the ignition coil for cylinder 5 is firing earlier than the expected timing.
Common Causes of the P1375 Code
The underlying cause depends entirely on the verified factory definition for the specific vehicle application.
For GM applications, possible causes include a failing ignition control module, a faulty crankshaft position sensor, damaged wiring in the 24X reference circuit, or a short to voltage.
For Honda applications, causes may involve a failing ignition coil on cylinder 5, damaged coil control wiring, poor electrical connections, or an internal engine control module driver fault.
Symptoms Associated With P1375
Symptoms vary depending on the underlying system fault and the vehicle manufacturer.
On GM applications with a 24X reference circuit fault, symptoms can include engine stalling, a no-start condition, rough idling, and an illuminated Check Engine Light.
On Honda applications with a cylinder 5 ignition fault, symptoms may include a noticeable misfire, hesitation during acceleration, reduced engine power, and a flashing or steady Check Engine Light.
Diagnosing the P1375 Trouble Code
Diagnosis must begin by confirming the exact factory definition for the specific make, model, and year.
For GM applications, technicians inspect the 24X reference circuit wiring for shorts to voltage or opens, test the ignition control module signals, and verify the crankshaft position sensor operation.
For Honda applications, technicians swap the cylinder 5 ignition coil to another cylinder to see if the misfire follows the component, then test the wiring and ECM signals.
Repairing the P1375 Issue
Repairs must follow confirmed diagnosis based on the specific vehicle application.
If an ignition control module or crankshaft position sensor fault is confirmed on a GM application, the confirmed failed component or damaged wiring must be replaced or repaired.
If an ignition coil or circuit fault is confirmed on a Honda application, the cylinder 5 ignition coil or damaged wiring must be replaced or repaired.
Cost Considerations for P1375 Repairs
Cost depends on diagnostic time, component accessibility, required parts, programming requirements, and labor.
Replacing an ignition coil or crankshaft position sensor may require minimal labor depending on accessibility.
Conversely, replacing an ignition control module or repairing a damaged engine wiring harness requires more labor and specialized diagnostic equipment.
Prevention Strategies for Future Occurrences
Some electrical and mechanical failures cannot be reliably prevented.
Inspecting exposed wiring harnesses for chafing or heat damage can help prevent intermittent circuit faults in the ignition or sensor systems.
Keeping connector seals intact may reduce moisture intrusion that leads to corrosion and signal loss.
Troubleshooting Tips and Best Practices
Never assume P1375 is a universal ignition or sensor code. Always verify the exact definition for the specific vehicle before purchasing parts.
Do not ignore related codes. A 24X reference fault may appear alongside other crankshaft or ignition control codes, while an ignition coil fault may appear alongside specific cylinder misfire codes.
Check for technical service bulletins applicable to your exact vehicle application, as manufacturers frequently release updated sensors or revised wiring harnesses for recurring faults.
More OBD-II Codes
| P1365 | P1377 | P1350 | P0300 |
| P1366 | P1378 | P1354 | P0335 |
| P1367 | P1380 | P1355 | P0340 |
| P1368 | P1381 | P1356 | P1345 |
| P1370 | P1382 | P1346 | P1347 |
| P1371 | P1386 | P1348 | P1349 |
Frequently Asked Questions
Is P1375 a generic or manufacturer-specific code?
No. P1375 is a manufacturer-specific code. Its exact definition varies significantly between automakers, so the factory service information for the specific vehicle must be consulted.
Can I drive my car with a P1375 code?
It depends on the application. If P1375 indicates a 24X reference circuit fault, the engine may stall or fail to start. If it is a cylinder 5 ignition fault, performance may be reduced.
Will disconnecting the battery clear the P1375 code?
Disconnecting the battery may temporarily clear the code, but it does not repair the underlying electrical or mechanical fault. The code will return once the monitor runs again.
Can a bad crankshaft position sensor cause a P1375 code?
On GM applications monitoring the 24X reference circuit, a failing crankshaft position sensor or ignition control module can cause the reference voltage to read abnormally high, triggering the fault code.
Does P1375 always mean the ignition coil or sensor is bad?
No. While a failing component is a cause on specific applications, the code can also indicate damaged wiring, a short to voltage, or poor electrical connections.
What Should You Do About the P1375 Code?
Confirm the exact factory definition and diagnostic procedure for your specific vehicle application. Because P1375 is manufacturer-specific, identifying whether it relates to a 24X reference circuit high voltage condition or a specific cylinder ignition coil fault is mandatory.
Follow the applicable manufacturer diagnostic steps to test the relevant system and components. Once the root cause is confirmed, complete the necessary repairs and verify that the system operates correctly and the code does not return.
