ICM And CKP/CMP Sensor Circuit Wiring Diagram (1996-1997 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: 1996, 1997.

Ignition Control Module (ICM)

The ignition control module is responsible for much more than simply firing the ignition coils. It powers the crankshaft position sensor, reads its signals, determines the correct coil firing sequence, and sends engine speed information to the PCM.

After the engine starts, the PCM takes over spark timing, but it still depends on the crankshaft signals supplied through the ignition control module.

Crankshaft Position Sensor (CKP)

The CKP sensor contains two Hall-effect switches inside one assembly. As the interrupter rings on the crankshaft balancer rotate past the sensor, they generate two separate digital signals.

The ignition control module constantly monitors both signals to determine crankshaft position and engine speed. Without both signals, the ICM can't properly trigger the ignition coils.

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

Camshaft Position Sensor (CMP)

The camshaft position sensor tells the PCM where cylinder #1 is in its firing cycle. This allows the PCM to control sequential fuel injection.

One failure that's extremely common on these engines is the camshaft magnet falling off the camshaft sprocket. The plastic carrier becomes brittle with age and eventually breaks, and the magnet falls off. This leaves the CMP sensor with nothing to detect. It's something you'll definitely want to inspect if you're diagnosing a CMP sensor code.

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.