Chevrolet Code P1377 – Ignition Control Module, Cam Reference Pulse to 4X, Incorrect Reference Pulse

Code P1377 Chevrolet Description

The diagnostic code P1377 (DTC) for Chevrolet vehicles indicates a problem with the camshaft reference pulse from the ignition control module (ICM) and the incorrect 4X reference pulse. This means there is a discrepancy between the signals sent from the camshaft position sensor to the ICM and the signals sent from the 4X reference pulse to the ICM. The ICM plays a crucial role in controlling the engine’s ignition timing, ensuring proper combustion and engine performance. When this code is triggered, it can lead to engine timing issues, misfires, and overall poor performance.

Common Causes of Chevrolet Code P1377

NOTE: The listed causes may not be a complete list of all potential issues, and there could be other causes.

1. Faulty camshaft position sensor
2. Faulty 4X reference pulse sensor
3. Wiring issues between the sensors and the ICM
4. Failing ignition control module (ICM)
5. Poor electrical connections

Symptoms of P1377 Chevrolet

1. Engine misfires
2. Rough idle or stalling
3. Decreased fuel efficiency
4. Check Engine light is on
5. Loss of power or acceleration

How to Fix Chevrolet Code P1377

1. Diagnose the issue using a scan tool to identify the exact cause of the code.
2. Inspect the camshaft position sensor, 4X reference pulse sensor, and wiring for any damage or corrosion.
3. Replace the faulty sensor or module identified during the diagnostic process.
4. Clear the code from the vehicle’s computer and perform a road test to ensure the issue is resolved.
5. If the problem persists, further diagnostics may be needed to address underlying issues.