ICM And CKP/CMP Sensor Circuit Wiring Diagram (1998-2000 3.8L V6 Buick LeSabre)

APPLIES TO: This ignition control module (ICM), CKP and CMP sensor circuit wiring diagram applies to the following vehicles:

• 3.8L V6 Buick LeSabre: 1998, 1999, 2000.

Ignition Control Module

The ignition control module receives the crankshaft position sensor signals and uses them to trigger the ignition coils. It also sends crankshaft position and RPM information to the PCM, which then controls ignition timing under normal operating conditions.

Without a valid crankshaft position signal, the ignition module won't fire the coils.

The crankshaft position sensor contains two Hall-effect switches that generate digital ON/OFF signals as the interrupter rings attached to the crankshaft balancer rotate past them.

The ignition control module compares these two signals to determine exactly where the crankshaft is at any given moment so it can fire the correct ignition coil.

CKP SENSOR TESTS: How To Test The CKP Sensor With A Multimeter (1994-2005 3.8L V6 Buick LeSabre).

Camshaft Position Sensor

The camshaft position sensor provides the PCM with a synchronization signal for sequential fuel injection. Even if this signal is lost, the engine will usually continue running using a backup injector strategy.

One thing that's worth checking is the camshaft gear magnet (behind the timing cover). The plastic mount that holds it (to the camshaft timing gear) is known for breaking, allowing the magnet to fall off the gear. When that happens, the CMP sensor can't generate its signal even though the wiring and sensor may both test good.

You can find a complete list of 3.8L V6 Buick LeSabre tutorials and wiring diagrams in this index:

• 3.8L V6 Buick LeSabre Index of Articles.