Pinpoint Test AO: Injector Control Pressure Too High: Introduction: Detection/Management: Notes

An open or shorted to ground control circuit can be detected by an on demand output circuit check performed during the KOEO test. When the starter is engaged and the engine fails to start, the IPR command will increase toward its maximum until the engine starts. The normal range for the IPR at idle is between 16-24%. An above 24% range indicates high effort to achieve idle. A below 16% indicates low effort to achieve idle.

The PCM is capable of detecting whether desired injection control pressure is equal to the measured injection control pressure while the engine is running. If the measured injection control pressure does not reasonably compare to the desired injection control pressure the PCM ignores the measured ICP sensor signal and attempts to control the engine with the desired value. (If the problem was in the sensor circuit, this strategy causes little performance deterioration. If the problem is in the control circuit, engine performance will probably still be unsatisfactory).

An injection control pressure step test, in which the PCM commands and then measures calibrated pressures, is performed during the KOER test.

CAUTION: The PCM harness connectors must be properly seated and the connector latch properly attached to eliminate possible driveability concerns or a no start condition. Installing the PCM connectors on an angle may cause an improper connection, misdiagnosis and damaged components. Install the connector until the lever pivots and seats itself. Apply light pressure to get the connector into position on the PCM and then fully seat the connector.

NOTE: Visually inspect the harness connectors for corrosion, damage, proper mating and correct pin tension.

NOTE: When the PCM is disconnected additional DTCs will be set. Clear all DTCs after restoring the vehicle.