Series 40E Troubleshooting – Section 10.15 Low Injection Control Pressure Test

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Figure 1. Diagnostic Form

Use this procedure to troubleshoot the low injection control pressure. For a reproduction of the applicable portion of the diagnostic form, see Figure
“Diagnostic Form”

, above. ‪

Section 10.15.1

The purpose of this procedure is to isolate the cause of low ICP pressure that prevents the engine from starting.‪

Section 10.15.2
Test Procedure

Before performing this test, repair all previously detected faults.‪

  1. Remove the engine harness connector from the EOT (Engine Oil Temperature) sensor located on the left rear of the front cover.
  2. Remove EOT sensor by loosening and carefully removing the sensor from the front cover. See Figure
    “Checking Oil Level in Oil Reservoir”
    . The sensor is positioned below the oil level in the reservoir. Removing the sensor will allow the oil in the reservoir to drain out of the opening. If little or no oil is present, refill the reservoir and install the EOT sensor and harness connector again. Crank the engine over to determine if it will start. If the engine does not start, proceed to the next step.

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    Figure 2. Checking Oil Level in Oil Reservoir

  3. Disconnect the high pressure oil hose from the high pressure oil manifold and install the adaptor from the Hydraulic Fitting Kit, J 43104, into the end of the hose. See Figure
    “Low ICP Pressure Test”

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    Figure 3. Low ICP Pressure Test

  4. Disconnect the engine harness connector from the ICP sensor located in the center of the high pressure oil manifold and remove the ICP sensor.
  5. Install the sensor into the adaptor located in the disconnected end of the high pressure oil hose.Note: If the EST is to be used for measuring ICP pressure, connect the ICP engine harness connector to the ICP sensor again. Monitor and record the ICP pressure while cranking the engine.

    Note: If the EST is unavailable, follow the remaining steps outlined below to perform the test.

  6. Install the Breakout T, J 43103, between the ICP sensor and the ICP engine harness connector.
  7. Connect the (+) lead of the DVOM to the green terminal and the (-) lead to the black terminal of the Breakout T.
  8. Monitor ICP pressure (signal voltage) while cranking the engine, and record on the diagnostic form.

If the ICP pressure is less than 500 lb/in.2
(psi) or 1 volt, perform the ICP Leakage Test. Refer to “10.15.3 ICP Leakage Test”

. If the ICP pressure remains low, perform the following steps:‪

  1. Remove the three cap screws that secure the transfer pump to the housing and pull the transfer pump away from the housing.
  2. Crank the engine and observe the transfer pump camshaft for rotation inside the housing. If the transfer pump camshaft is not rotating, remove the high pressure pump and tighten the loose drive gear. Install the high pressure pump again. Check the ICP pressure while cranking the engine, again.
  3. If the pressure is still low, replace the IPR valve and check the ICP pressure again.
  4. If pressure is still low, replace the high pressure oil pump.

Section 10.15.3
ICP Leakage Test

Perform the leakage test using the following procedure:‪

  1. Remove intake manifold/valve cover.
  2. Remove ICP sensor and adaptor plug (used previously) from the high pressure hose. Attach the hose to the oil manifold. Remove the other end of the hose from the high pressure pump and connect an air pressure regulator to the (removed) hose as shown. See Figure
    “ICP Leakage Test”

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    Figure 4. ICP Leakage Test

  3. Apply 100 lb/in.2
    of air pressure to the oil manifold.
  4. Inspect for leakage around the injectors.
  5. With the fuel lines removed from the fuel manifold, inspect for oil leakage out of each end of the fuel manifold.

If leakage is observed at an injector, remove and inspect the injector for obvious damage or worn O-rings.‪

If no leakage is present, perform Injector Buzz Test with air pressure still applied. Observe oil discharge from each of the injectors. Oil discharge should be equal from all injectors. If excess oil is discharged from an injector(s), the injector(s) may be defective.‪

If it is difficult to distinguish which injector(s) are leaking, remove the air supply and the regulator from the high pressure hose and:‪

  1. Connect an automotive cylinder leak tester to the high pressure hose and apply air pressure via the cylinder leak tester.
  2. Conduct an Injector Buzz Test and observe the percent of cylinder leakage while each injector is actuated. Remove and inspect injectors that exhibit a greater amount of leakage compared to the others.
  3. If none of the injectors indicate an excessive amount of leakage, remove all injectors. Inspect all O-rings for wear and damage. All O-rings should be replaced.

If oil was entering the fuel system drain the fuel tanks and dispose of the contaminated fuel properly.‪

Section 10.15.4
Possible Causes

Low injection pressure (voltage) indicates the injectors are not receiving sufficient oil pressure to operate properly. This may be caused by:‪

  • No oil in the engine
  • Oil reservoir leak down (possibly through high pressure pump check valve)
  • Defective high pressure pump
  • Injector O-ring leak
  • Injector body leak
  • IPR valve stuck open
  • Pump drive gear loose or damaged

Section 10.15.5
Tools Required

Pro-Link 9000 or DVOM and ICP sensor breakout Tee, J 43103
, and an ICP adaptor fitting from the Hydraulic Fitting Kit, J 43104

Section 10.15.6
Supplemental Diagnostics

Camshaft Position sensor diagnostics, refer to “19.1 Functions”


Series 40E Troubleshooting Manual – 6SE241
Generated on 10-13-2008