Test Notes

IPR And Related Components:

OUTPUT FUNCTIONS
The Injection Pressure Regulator (IPR) is a variable position valve that controls Injection Control Pressure (ICP). The Powertrain Control Module (PCM) uses many input variables to determine the desired injection control pressure.

Battery voltage is supplied to the IPR when the ignition key is in the ON position. Valve position is controlled by switching the output signal circuit to ground inside the PCM. ON/OFF time is modulated from 0 to 60% dependent upon the desired injection control pressure.

Test Schematic:

DETECTION/MANAGEMENT
An open or shorted to ground control circuit can be detected by an on demand output circuit check performed during the KOEO test.

The PCM is capable of detecting whether desired injection control pressure is equal to 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 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 specific preprogrammed pressures is performed during the Key On Engine Running (KOER) test.

NOTE: The engine will not operate with an IPR circuit that is not functioning.





Harness Connector Checks To Ground (B-)
Check with IPR connector disconnected and ignition key and all accessories OFF.





IPR Voltage Check
Check with regulator connector disconnected.





Harness Resistance Checks
Check with Breakout Box installed on harness only.

NOTE: After removing connectors always check for damaged pins, corrosion, loose terminals, etc..

DTC DESCRIPTIONS
1282 = ICP pressure was greater than 3675 psi for 1.5 seconds (possible grounded IPR control circuit).
1283 = Output circuit check detected during KOEO test; indicates high or low resistance in circuit.
1211 = If set during normal engine operation indicates engine is operating in open loop control and ICP pressure is above or below desired pressure. If set during KOER test, indicates ICP system failed step test and could not maintain commanded pressure.