What does it mean?
P1370 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: IC Module 4X Reference Circuit Too Many Pulses .
Symptoms
- Engine cuts out or stumbles while driving, sometimes clearing on its own
- Hard starting or intermittent no-start conditions
- Erratic tachometer movement that does not match engine speed
- Misfire-like surging under load and poor throttle response
- Check engine light on, often together with crank signal or misfire codes
Likely causes
- Electrical interference coupled into the reference circuit from spark plug leads or a failing coil arcing to ground
- Damaged or unshielded reference wire routed too close to ignition secondary components
- Crankshaft position sensor producing a noisy or distorted output
- Reluctor ring with damaged, chipped or contaminated teeth generating extra transitions
- Poor engine-to-body or module ground raising noise on the reference line
- Corroded or loose connector at the ignition control module or the sensor
- Failed ignition control module misreading or generating spurious pulses
How to fix it
- Inspect the spark plug leads, boots and coils for arcing, since secondary leakage is a classic source of false pulses
- Check the routing of the reference circuit and keep it separated from ignition secondary wiring
- Clean and tighten the engine and module ground connections, then retest
- Inspect the crank sensor tip and mounting for debris, damage and correct air gap
- Scope the reference signal, looking for extra transitions or noise riding on the waveform
- Examine the reluctor ring for chipped or contaminated teeth if the noise repeats at a fixed point per revolution
- Replace the crank sensor or the ignition control module according to the test results, then verify a clean reference signal at idle and under load