With Special Tool

CIRCUIT DESCRIPTION
Each ignition coil is responsible for supplying secondary energy to a pair of spark plugs. This is a waste spark ignition system. The ignition control (IC) signals output by the powertrain control module (PCM) are amplified by the ignition control module (ICM) in order to fire each coil. The spark events are triggered by the ICM, but the module has no influence on spark timing. The ICM is also responsible for detecting and supplying a CAM signal pulse to the PCM to be used for sequential fuel injection. This ignition system does not use a conventional camshaft position (CMP) sensor that detects valve train position. The ICM detects when #1 or #3 cylinder has fired on its compression stroke using sensing circuitry integrated within each coil. The sensing circuit detects the polarity and the strength of the secondary voltage output. The higher output is always at the event cylinder. The ICM sends a CAM signal to the PCM based on the voltage difference between the event and waste cylinder firing energy. This system is called compression sense ignition. By monitoring the CAM signals, the PCM can accurately time the operation of the fuel injectors.

This system consists of the following circuits:
^ Ignition 1 voltage
^ Ground
^ Camshaft position (CMP) sensor signal
^ IC timing control-2/3
^ IC timing control-1/4

DIAGNOSTIC AIDS
^ A small amount of resistance in the battery positive voltage circuit to the PCM may cause a no start. Test the battery positive voltage circuit for excessive resistance or corrosion. Refer to Wiring Repairs in Diagnostic Aids.
^ The PCM grounds will cause a no start only if all of them are not making a good connection. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.
^ If the crankshaft position (CKP) sensor is loose the sensor may cause an intermitted no start by moving away from the reluctor wheel.

TEST DESCRIPTION

Steps 1-8:

Steps 9-15:

Steps 16-26:

4. This step test for a short to voltage in the ignition circuit.
5. This step test for a short to voltage in the battery circuit.