Pinpoint Test X: Injection Pressure Regulator: Description

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Injection Pressure Regulator (IPR) is a variable position valve that controls injection control pressure. Powertrain Control Module (PCM) uses many input variables to determine desired injection control pressure. Battery voltage is supplied to IPR when ignition on. Valve position is controlled by switching output signal circuit to ground inside PCM. ON/OFF time is modulated from 0-50 percent, dependent upon desired injection control pressure. An open or shorted to ground control circuit can be detected by a KOEO OUTPUT STATE SELF-TEST under QUICK TEST. PCM is capable of detecting whether desired injection control pressure is equal to measured injection control pressure while engine is running. If measured injection control pressure does not compare to desired injection control pressure, PCM ignores measured ICP sensor signal and attempts to control engine speed with desired value.

If problem is in sensor circuit, this strategy causes little performance deterioration. If problem is in control circuit, engine performance will probably still be unsatisfactory. An injection control pressure step test, in which PCM commands and then measures specific preprogrammed pressures, is performed during KOER SELF-TEST . If DTC 1211 is set during normal engine operation, it indicates engine is operating in open-loop control and injection control pressure is more or less than desired pressure. If DTC 1211 is set during KOER self-test, it indicates ICP system failed step test and could not maintain commanded pressure. DTC 1282 indicates injection control pressure was more than 3,675 psi for 1.5 seconds (possible grounded IPR control circuit). If concern is not electronic, diagnose injection control pressure. Perform INJECTION CONTROL PRESSURE TEST and check for pressurized oil leaks. See HARD START/NO START DIAGNOSIS in I - SYSTEM & COMPONENT TESTS - 7.3L DIESEL article. DTC 1283 indicates high or low resistance in circuit during KOEO OUTPUT STATE SELF-TEST.

Perform this test when directed here by QUICK TEST. This pinpoint test is intended to diagnose:

Injection Pressure Regulator (IPR).
Injection Control Pressure (ICP) sensor.
Powertrain Control Module (PCM).
Wiring harness circuit (IPR).

Fig 1: Injection Pressure Regulator Circuit Checks & Terminal Identification (1 Of 2)

Courtesy of FORD MOTOR CO.

Fig 2: Injection Pressure Regulator Circuit Checks & Terminal Identification (2 Of 2)

Courtesy of FORD MOTOR CO.