10e. Monitor The ICP and IPR Duty Cycle While Cranking

10e. MONITOR THE ICP AND IPR DUTY CYCLE WHILE CRANKING

NOTE:
- If the IPR screen is damaged or debris is present, clean or install a new screen as necessary and retest the system. Do not install a new high pressure oil pump due to debris being present on the screen.
- A complaint of engine stalls when warm followed by a crank no start indicates a high pressure oil system concern. This may be accompanied by DTC P2290 with or without DTC P2291. Follow this procedure to isolate the cause of the concern.
- Higher oil temperatures are more effective to diagnose high pressure oil system leaks.

Purpose:
The purpose of this test is to determine if the injection control pressure (ICP) system can supply sufficient injection control pressure to sustain starting and to determine if oil leaks are present in the high pressure oil system.

Data List
- The scan tool may reset below 9.5 volts.
- Select the parameters indicated from the scan tool parameter list and monitor while cranking the engine.







Recommended Procedure:
- Connect the scan tool.
- Ignition ON, engine OFF.
- Access and monitor the ICP, ICP_DES, IPR, EOT and RPM PIDS.
- If the ICP voltage is not between 0.15 and 0.35 volts with the ignition ON, engine OFF, GO to Pinpoint Test Q. Test Q: Injection Control Pressure (ICP) Sensor
- If the engine does not start, disconnect the ICP sensor connector and attempt to start the engine. If the engine starts with the ICP sensor disconnected, GO to Pinpoint Test Q. Test Q: Injection Control Pressure (ICP) Sensor
- If the engine does not start with the ICP sensor disconnected, carry out the High Pressure Oil System Air Pressure Check. 10f. High Pressure Oil System Air Pressure Check
- If the engine starts, warm the engine up until the EOT temperature is greater than 80°C (176°F), then turn the ignition to the OFF position.
- If the ICP sensor connector is disconnected, connect the ICP sensor connector.
- Crank the engine and attempt to restart.
- Compare the PID data to the specification and the graphs during engine start-up.

NOTE: A CKP signal is required before the IPR is commanded above 14%.

If the ICP does not meet the minimum specification of 3.5 MPa (500 psi), the injectors are not enabled by the PCM because of insufficient rail pressure.

If the IPR duty cycle is greater than the specification at warm idle, a leak in the high pressure oil system is suspect. Carry out the High Pressure Oil System Air Pressure Check. 10f. High Pressure Oil System Air Pressure Check

If the IPR duty cycle is greater than 14%, ICP pressure should increase above 3.5 MPa (500 psi) provided that the IPR valve is not stuck open, the high pressure pump is building pressure and there is not an injection control pressure system leak between the high pressure pump and the injectors.

Not all high injection control pressure oil system issues result in a no start condition. Intermittent hard start or slow start conditions may be the result of a small leak in the injection control pressure system.

If the oil is leaking from the ICP system or if air is trapped in the ICP system, the IPR valve may be commanded fully closed (85% duty cycle) while the starter is engaged in an attempt to exceed 3.5 MPa (500 psi). Monitoring RPM, IPR duty cycle, and ICP while cranking the engine, after 5 minute soak, may assist in ICP system diagnosis. ICP system leaks results in no start, hard start, slow start or intermittent hard start conditions. The symptoms caused by small leaks are present only with excessive ICP after engine start and are more prevalent on warm engines when the oil viscosity is lower.

Good Start Expected Response:

A sharp increase in IPR duty cycle followed by a steep rise in ICP pressure is expected. If the ICP and IPR response resemble the Good Start Expected Response as shown, carry out the Injection Pressure Regulator Test. 12b. Injection Pressure Regulator Test

Hard Start, Stall, No Start Engine Hot, Entrapped Air Or Oil Leak Expected Response:

If the ICP and IPR response resemble the Hard Start, Stall, No Start Engine Hot, Entrapped Air or Oil Leak Expected Response as shown, carry out the High Pressure Oil System Air Pressure Check. 10f. High Pressure Oil System Air Pressure Check

No Start Or Oil Leak Expected Response:

If the ICP and IPR response resemble the No Start or Oil Leak Expected Response as shown, carry out the High Pressure Oil System Air Pressure Check. 10f. High Pressure Oil System Air Pressure Check

Possible Causes:
- Low base engine oil pressure or level
- ICP system leak
- Damaged discharge tube
- Damaged high pressure oil branch tube
- Leaking high pressure tube assembly male and female fitting
- Damaged stand-pipe or oil supply tube
- Damaged or missing stand-pipe O-ring
- Damaged or missing oil supply tube O-ring
- Damaged high pressure oil rail plug
- Damaged or missing high pressure oil rail plug O-ring
- Damaged or missing O-ring between discharge tube and high pressure pump
- Damaged or missing discharge tube O-ring that fits inside high pressure pump cover
- Damaged or missing high pressure pump inlet O-ring
- Damaged or missing O-ring between high pressure oil rail and the injector
- IPR failure
- Damaged high pressure pump

Possible Leak Locations

High Pressure Oil System: