Injection Pressure Regulator (IPR)

1996 PCED OBDI

SECTION 18: Diesel Diagnosis — 7.3L DI Engine

X: Injection Pressure Regulator (IPR)

X1 DIAGNOSTIC TROUBLE CODE (DTC) 1283: CHECK POWER FEED

DTC 1283 indicates an IPR circuit failure was detected by the PCM.
Key off.
Remove IPR harness connector.
Remove PCM relay.
Measure resistance from IPR connector Pin A to PCM relay terminal 361 (R).

Is resistance less than 5 ohms?

Yes	No
GO to X2.	SERVICE open Circuit 361 (R). RERUN Scan Tool Diagnostic Test.

X2 CHECK IPR COIL RESISTANCE

Measure resistance of IPR coil.

Is resistance 5 to 20 ohms?

Yes	No
GO to X3.	REPLACE IPR. RERUN test.

X3 IPR CONTROL CIRCUIT SHORT TO POWER OR GROUND

Install breakout box. Leave the PCM disconnected.
Leave IPR disconnected.
Key off.
Measure resistance from Test Pin 83 to power at Test Pins 71 and 97.
Measure resistance from Test Pin 83 to ground at Test Pins 25, 51, 76, 77 and 103.

Is the resistance greater than 10,000 ohms?

Yes	No
GO to X4.	REPAIR short in Circuit 552 (Y/R). RERUN Scan Tool Diagnostic Test.

X4 IPR HARNESS CONTROL CIRCUIT — CONTINUITY

Install breakout box. Leave the PCM disconnected.
Measure continuity from PCM Pin 83 to Point B in the IPR regulator harness connector.

Is there continuity?

Yes	No
REPLACE PCM. RETEST.	SERVICE open Circuit 552 (Y/R). RERUN test.

X5 DIAGNOSTIC TROUBLE CODE (DTC) 1282: EXCESSIVE INJECTION CONTROL PRESSURE

DTC 1282 indicates excessive injection control pressure was detected during continuous diagnostic monitoring.
Possible causes:

Intermittent IPR control circuit short to ground
Stuck IPR

Key off.
Disconnect IPR harness connector.

Will engine start?

Yes	No
REPLACE IPR. RERUN Scan Tool Diagnostic Test.	GO to X6.

X6 CHECK FOR INTERMITTENT SHORT TO GROUND

Install breakout box. Leave the PCM disconnected and leave IPR disconnected.
Measure resistance from PCM Pin 83 to ground.
Wiggle IPR circuit connectors and wires to attempt to induce short to ground.

Is there resistance greater than 10,000 ohms?

Yes	No
CLEAR codes. RERUN KOER test. If codes return, REPLACE PCM.	REPAIR short to ground.

X7 KOER ON-DEMAND DIAGNOSTIC TROUBLE CODE (DTC) 1211

DTC 1211 indicates that injection control pressure was below command desired during self test mode.
Possible causes:

Low reservoir oil level
Poor oil quality
Injector O-ring leak
Faulty IPR valve
Faulty ICP sensor
Faulty high pressure oil pump
Faulty PCM

Perform KOEO On-Demand Self Test.

Are any DTCs present?

Yes	No
REPAIR KOEO DTCs as required. RETEST system.	GO to X8.

X8 CHECK OIL RESERVOIR LEVEL

Remove plug in top of oil reservoir and check level.

Is oil level within 25.4mm (1 inch) of the top of the reservoir?

Yes	No
GO to X9.	REPAIR condition causing low oil supply to the reservoir. RETEST system.

X9 ICP SENSOR CHECK

NGS Tester installed.
Key on.
Monitor ICP PID on the NGS Tester.

Is ICP reading 0 psi?

Yes	No
GO to X10.	REPLACE faulty ICP sensor. RETEST system.

X10 OIL AERATION CHECK

NGS Tester installed.
Monitor ICP PID.
Accelerate engine to wide-open throttle and hold for three minutes.

Does ICP reading increase above 1250 psi?

Yes	No
CHANGE engine oil and REPEAT test.	GO to X11.

X11 CHECK ICP WHILE PERFORMING SELF TEST

Install ICP/EBP Adapter Cable D94T-50-A or equivalent between ICP sensor and engine harness.
Measure the voltage between ICP signal circuit and ground.
Perform KOER On-Demand Self Test.

Does voltage reading increase above 3v and then decrease to approximately 1v during the ICP portion of the test?

Yes	No
If DTC 1211 was displayed, REPLACE the PCM. RETEST system.	GO to X12.

X12 INJECTOR LEAK TEST

Disconnect high pressure hose from right cylinder head.
Using Oil High Pressure Leakage Adapter Set D94T-6600-A or equivalent, plug right high pressure hose.
Monitor IPR PID on NGS Tester.
Start vehicle and record IPR reading on NGS Tester.
Engine off.
Reconnect right cylinder head high pressure hose.
Disconnect left cylinder head high pressure hose. Install adapter and ICP into high pressure hose.
Start vehicle and record IPR reading on NGS Tester.

Are the two readings within 2% of each other?

Yes	No
REPLACE faulty IPR valve. RETEST system. If DTC 1211 is still present, GO to X13.	REPAIR internal oil leak on the bank with the higher IPR reading. REFER to Section 03-04D in the Powertrain, Drivetrain Service Manual for inspection and repair methods.

X13 OIL SYSTEM PRESSURE TEST

Refer to Section 03-03 of the Powertrain, Drivetrain Service Manual and perform pressurized oil leak checks per procedures listed.

Is a leak condition indicated?

Yes	No
REPAIR leak as necessary.	REPLACE high pressure oil pump.

X14 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) 1211

DTC 1211 indicates injection control pressure was above or below desired level under normal driving conditions.
Possible causes:

Low reservoir oil level
Poor oil quality
Injector O-ring leak
Faulty IPR valve
Faulty high pressure oil pump
Faulty PCM

Perform KOEO On-Demand Self Test.

Are any DTCs present?

Yes	No
GO to appropriate Pinpoint Test for repair.	GO to X15.

X15 CHECK OIL LEVEL IN RESERVOIR

Remove plug from top of oil reservoir and check level.

Is oil level within 25.4mm (1 inch) of the top of the reservoir?

Yes	No
GO to X16.	REPAIR condition causing low oil supply to the reservoir. RETEST system.

X16 ICP SENSOR CHECK

NGS Tester installed.
Key on.
Monitor ICP PID on NGS Tester.

Is injection control pressure reading 0 psi?

Yes	No
GO to X17.	REPLACE faulty ICP sensor. RETEST system.

X17 OIL AERATION CHECK

NGS Tester installed.
Monitor ICP PID.
Accelerate engine and hold at WOT for three minutes.

Does injection control pressure reading increase above 1250 psi?

Yes	No
CHANGE engine oil. RETEST system.	GO to X18.

X18 PERFORM KOER ON-DEMAND SELF TEST

Perform KOER On-Demand Self Test.

Is a 1211 fault indicated?

Yes	No
GO to X11.	Unable to duplicate failure at this time.