ICM And 7X CKP Sensor Circuit Wiring Diagram (1996 3.1L V6 Buick Century)

APPLIES TO: This ignition control module (ICM) and 7X CKP sensor circuit wiring diagram applies to the following vehicles:

• 3.1L V6 Buick Century: 1996.

The 7X Crankshaft Position Sensor

The 7X crankshaft position sensor is mounted low on the rear of the engine block, below the rear exhaust manifold, on the side of the engine facing the firewall.

As the crankshaft rotates, the sensor generates its own AC voltage signal. That signal is sent directly to the ignition control module (ICM). The sensor does not communicate directly with the PCM.

The ignition control module depends on this signal to determine crankshaft position during cranking. If the signal is missing, the ignition coils won't fire and the engine won't start.

3X CKP SENSOR TESTS: How To Test The 7X Crankshaft Position Sensor (1994-2005 3.1L V6 Buick Century).

The Ignition Control Module (ICM)

The ignition control module is mounted beneath the three ignition coils on top of the rear valve cover.

Using the signal from the 7X CKP sensor, the ICM determines the proper coil firing sequence during engine startup. It also creates the 3X crankshaft reference signal that the PCM uses for engine RPM, fuel injector control, and ignition timing calculations.

The 3X reference signal (that the ICM sends the PCM) is a digital pulse that switches ON and OFF three times during each crankshaft revolution.

ICM DIAGNOSTIC TESTS: Testing The Ignition Module And Crank Sensor (GM 3.1L, 3.4L) (at: easyautodiagnostics.com).

Ignition Coils

The ignition control module supports three separate twin-tower ignition coils. Each coil is responsible for firing a pair of spark plugs simultaneously using the waste-spark system.

Each coil has two electrical connections. One terminal receives fused battery voltage, while the ignition control module controls the other terminal by switching its Ground ON and OFF to create spark.

In my experience, the two most common ignition coil failures are:

• Only one of the two towers produces spark.
• Both towers stop producing spark because the coil has failed internally.

Each ignition coil can be replaced individually without replacing the other two coils.

IGNITION COIL TESTS: How To Test The Ignition Coil Packs (GM 3.1L, 3.4L) (at: easyautodiagnostics.com).

Other 7X CKP Sensor Wiring Diagrams

• ICM And 3X CKP Sensor Circuit Wiring Diagram (1994-1995 3.1L V6 Buick Century).
• ICM And 7X CKP Sensor Circuit Wiring Diagram (1997 3.1L V6 Buick Century).
• ICM And 7X CKP Sensor Circuit Wiring Diagram (1998-2005 3.1L V6 Buick Century).

More 3.1L V6 Buick Century Tutorials

You can find a complete list of 3.1L V6 Buick Century tutorials and wiring diagrams in this index:

• 3.1L V6 Buick Century Index of Articles.

Here's a sample of the tutorials you'll find in the index:

• How To Test The TPS With A Multimeter (1997-2005 3.1L V6 Buick Century).
• Common Causes Of Spark Plug Failure (1994-2005 3.1L V6 Buick Century).
• How To Test For A Blown Head Gasket (1994-2005 3.1L V6 Buick Century).
• How To Test Engine Compression (1994-2005 3.1L V6 Buick Century).