12b. Injection Pressure Regulator Test

12b. INJECTION PRESSURE REGULATOR TEST

NOTE:
- Do not replace the high pressure oil pump if debris is present on the IPR screen. Clean or replace the screen, reinstall the IPR valve, and retest the IPR valve function.
- If oil is leaking from the high pressure oil system or if air is trapped in the system, the injection pressure regulator (IPR) valve may be commanded fully closed (85% duty cycle) by the powertrain control module (PCM) during cranking in an attempt to exceed 3.5 MPa (500 psi).
- If DTC 2623 is present, GO to Pinpoint Test R. Test R: Injection Pressure Regulator (IPR)
- The engine must be at normal operating temperature to verify IPR duty cycle.

Purpose:
The purpose of this test is to determine if idle stability or low power is caused by a stuck or dirty IPR.

Injection Pressure Regulator Test
- Check during startup and at low idle with EOT above 80°C (176°F).
- Monitor the IPR PID with the scan tool.







Recommended Procedure:
- Connect the scan tool.
- Access and monitor the ICP, IPR, RPM, and EOT PIDs.
- Key ON, engine running.
- Warm the engine until the EOT is greater than 80°C (176°F).
- Operate the engine at low idle speed.
- Key OFF.
- Key ON, engine running.
- Compare the ICP PID data to the graph during engine startup.

Good Start Expected Response:

- ICP should reach 3.5 MPa (500 psi) within a few seconds of cranking engine.
- A sharp rise in IPR duty cycle should be present followed by a steep rise in ICP pressure.
- Next, carry out a slow neutral run-up in park or neutral to 4000 RPM.

If the ICP and IPR response resembles the figure and the engine runs rough between 1200 and 2300 RPM, carry out the Check Valve Operation Test. 12c. Check Valve Operation Test

If the ICP and IPR response resembles the figure and the engine runs rough between 3000 and 4000 RPM, replace the IPR valve and verify the repair.

If any of the following symptoms are present, go to the High Pressure Oil System Air Pressure Check. Repair any leaks in the high pressure oil system and return to this test to verify IPR operation. 10f. High Pressure Oil System Air Pressure Check

- A. slow or unresponsive ICP pressure
- The engine will not start when warm
- The IPR duty cycle is greater than the maximum specification
- Engine does not run rough and the ICP pressure response does not resemble the graph

Possible Causes:
- Debris stuck in the IPR
- High pressure oil system leak

Tools Required:
Scan tool