P1374

Description
3X REFERENCE CIRCUIT

3X reference circuit is produced by Ignition Control Module
(ICM). PCM uses 3X reference signal pulses to calculate engine speed
(RPM) and crankshaft position at engine speed more than 1200 RPM. PCM
uses pulses on this circuit to initiate injector pulses. If PCM
receives incorrect number of pulses on 3X reference circuit, DTC P1374
will set.

Symptoms
You likely won't notice any drivability problems.

Causes

• Engine running and PCM is receiving 18X reference signal
  pulses.
• Ratio of 18X reference signal pulses to 3X reference signal
  pulses received by PCM do not equal 6.
• Ratio of 18X reference signal pulses to camshaft reference
  signal pulses received by PCM equals 36.

Solutions

• Check for faulty 3X reference signal circuit connection at
  PCM. Repair as necessary.
• Check for incorrect harness routing near secondary
  ignition components, ignition coil arcing to wiring harness or ICM.
• Check ignition coils for cracks, carbon tracking or other signs of
  damage.
• Check for faulty connections at ICM.
• Replace ICM.