1997 PCED OBDII-Diesel | SECTION 5C: Pinpoint Tests |
X1 DIAGNOSTIC TROUBLE CODE (DTC) P1283: CHECK POWER FEED
- DTC P1283 indicates an IPR circuit failure was detected by the PCM.
- Key off.
- Remove IPR harness connector.
- Remove PCM relay.
- Measure resistance between IPR connector Pin A and 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 PCM disconnected.
- Leave IPR disconnected.
- Key off.
- Measure resistance between Test Pin 83 and Test Pins 71 and 97.
- Measure resistance between Test Pin 83 and Test Pins 25, 51, 76, 77 and 103.
Is 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 — RESISTANCE
- Install breakout box. Leave PCM disconnected.
- Measure resistance between PCM Pin 83 and Point B in the IPR regulator harness connector.
Is resistance less than 5 ohms?
Yes | No |
REPLACE PCM. RETEST. | SERVICE open Circuit 552 (Y/R). RERUN test. |
X5 DIAGNOSTIC TROUBLE CODE (DTC) P1282: EXCESSIVE INJECTION CONTROL PRESSURE
- DTC P1282 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 between PCM Pin 83 and ground.
- Wiggle IPR circuit connectors and wires to attempt to induce short to ground.
Is 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) P1211
- DTC P1211 indicates that injection control pressure was above or below commanded desired pressure during self test mode.
- Possible causes:
- incorrect oil or viscosity
- poor oil quality
- gel fuel/no fuel
- low fuel pressure
- damaged IPR valve
- high-pressure oil system leak
- damaged high-pressure oil pump
- damaged PCM
- Verify correct oil quality/viscosity and correct fuel grade are being used for the temperature conditions.
Is oil and fuel quality OK?
Yes | No |
GO to X8. | SERVICE fuel or oil condition and VERIFY DTC does not return. |
X8 CHECK FUEL PRESSURE
- Measure fuel pressure at regulator block.
- Measure fuel pressure at idle and on road at WOT at full load. Fuel pressure at idle should be 138 kPa (20 psi) minimum, and 206-482 kPa (30-70 psi) at WOT full load.
Is fuel pressure OK?
Yes | No |
GO to X9. | SERVICE fuel system concern. CLEAR DTC and RETEST. |
X9 CHECK OIL RESERVOIR LEVEL
- Remove plug in top of oil reservoir and check level.
Is oil level within 25.4 mm (1 inch) of the top of the reservoir?
Yes | No |
GO to X10. | REPAIR condition causing low oil supply to the reservoir. RETEST system. |
X10 ICP SENSOR CHECK
- NGS Tester installed.
- Key on.
- Monitor ICP PID on the NGS Tester.
Is ICP reading 0 kPa (0 psi)?
Yes | No |
GO to X11. | REPLACE faulty ICP sensor. RETEST system. |
X11 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 8618 kPa (1250 psi)?
Yes | No |
CHANGE engine oil and REPEAT test. | GO to X12. |
X12 CHECK ICP WHILE PERFORMING SELF TEST
Note: During KOER On-Demand Self Test, ICP will be commanded high (17 mpa), then low (5 mpa) and then EBP will be commanded high and low.
- 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 KOER test?
Yes | No |
If DTC 1211 was displayed, REPLACE the PCM. RETEST system. | GO to X13. |
X13 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 X14. | REPAIR internal oil leak on the bank with the higher IPR reading. REFER to the Powertrain/Engine Group in the Service Manual. |
X14 OIL SYSTEM PRESSURE TEST
- Go to the Powertrain/Engine Group in the Service Manual. Perform pressurized oil leak checks.
Is a leak condition indicated?
Yes | No |
REPAIR leak as necessary. | REPLACE high pressure oil pump. |
X15 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) P1211, P1209
- DTC P1209 and P1211 indicates that injection control pressure was above or below desired level under normal driving conditions.
- Possible causes:
- incorrect oil or viscosity
- poor oil quality
- gel fuel/no fuel
- low fuel pressure
- damaged IPR valve
- high-pressure oil system leak
- damaged high-pressure oil pump
- damaged PCM
- Verify correct oil quality/viscosity and correct fuel grade are being used for the temperature conditions.
Is oil and fuel quality OK?
Yes | No |
GO to X16. | SERVICE fuel or oil condition. CLEAR DTC and RETEST. |
X16 RECHECK FUEL PRESSURE
- Measure fuel pressure at regulator block.
- Measure fuel pressure at idle and on road at WOT full load. Fuel pressure at idle should be 138 kPa (20 psi) minimum, and 206-482 kPa (30-70 psi) at WOT full load.
Is fuel pressure OK?
Yes | No |
GO to X17. | SERVICE fuel system concern. CLEAR DTC and RETEST. |
X17 PERFORM KOER ON-DEMAND SELF TEST
- Perform KOER On-Demand Self Test.
Is DTC P1211 set?
Yes | No |
GO to X9. | GO to X18. |
X18 CHECK OIL LEVEL IN RESERVOIR
Is oil level within 25.4 mm (1 inch) of the top of the reservoir?
Yes | No |
GO to X19. | REPAIR condition causing low oil supply to the reservoir. RETEST system. |
X19 CHECK ICP SENSOR
- NGS Tester installed.
- Key on.
- Monitor ICP PID on NGS Tester.
Is injection control pressure reading 0 kPa (0 psi)?
Yes | No |
GO to X20. | REPLACE faulty ICP sensor. RETEST system. |
X20 CHECK OIL AERATION
- NGS Tester installed.
- Monitor ICP PID.
- Accelerate engine and hold at 3300 rpm for three minutes.
Does injection control pressure reading increase above 8618 kPa (1250 psi)?
Yes | No |
CHANGE engine oil. RETEST system. | GO to X21. |
X21 CHECK IPR DUTY CYCLE UNDER LOAD
- NGS scan tool installed.
- Monitor ICP and IPR PIDs.
- Run vehicle at WOT and full load condition.
Does IPR duty increase to 65%?
Yes | No |
REPLACE IPR valve. CLEAR DTC and RETEST. | Unable to duplicate failure. |