Posted on October 28, 2020
Use the steps that follow to check the operation of the HEUI fuel system. Circle the appropriate answers within the “Results” section of each step. Complete the pages. Provide completed pages with any returned part. Return the parts through the normal channels.
Results from the test must be included in the claim for related repairs. Failure to follow the proper sequence of this procedure may result in incorrect results. The standard warranty may not cover repairs that are performed while using this procedure incorrectly.
Illustration 1 g01181491
Left side of engine (typical example)
(1) J500/P500 Connector for the injection actuation pressure control valve
(2) Injection actuation pressure sensor
| Troubleshooting Test Steps | Values | Results |
| 1. Check for CodesA.Connect the Cat®Electronic Technician (ET) to the data link connector. B.Turn the keyswitch to the ON position.DO NOT START THE ENGINE. C.Print the “Lifetime Totals” and the “Configuration” screen. D.Check for active diagnostic codes or logged diagnostic codes. The diagnostic codes should become active within 30 seconds. E.Verify that the engine coolant temperature sensor is operating properly. Verify through Cat ET. Refer to Testing and Adjusting, “Test For The Water Temperature Gauge” for the proper procedure. Document all active diagnostic codes or logged diagnostic codes. | Codes | Results:There are no active codes or logged codes. Proceed to Test Step 2.Results:Active codes or logged codes are present. Repair:Troubleshoot the codes as required. STOP |
| 2. Start the EngineA.Inspect the engine for oil leaks in the HEUI oil rail. Repair leaks before proceeding. Clearly mark all leaks on returned parts. Note:Inspect the area near the high-pressure oil rail and the unit injector hydraulic pump. If leakage is found between the transfer pump and the hydraulic pump, refer to Special Instructions, REHS3830 for details. If leakage is found between the hydraulic pump and the front housing, refer to Special Instructions, REHS3830 for details on replacing the seal. B.Check the engine oil level. If the engine oil level is low, add oil to the engine. Do not overfill the engine. C.Try to start the engine. | Engine | Results:The engine starts. Proceed to Test Step 10.Results:The engine does not start. Proceed to Test Step 3. |
| 3.Verify the Operation of the Injection Actuation Pressure SensorA.Disconnect the connector for the injection actuation pressure sensor. Check for evidence of moisture in the connector. Refer to Troubleshooting, “Electrical Connectors – Inspect” for troubleshooting details. B.Try to start the engine. | Injection Actuation Pressure Sensor | Results:The engine does not start. Reconnect the connector for the actuation pressure sensor. Clear all diagnostic codes. Proceed to Test Step 4.Results:The engine starts. Repair:The injection actuation pressure sensor may be faulty. Replace the sensor and reconnect the connector. Clear all diagnostic codes. Verify that the repair eliminates the problem. If the problem still exists, proceed to Test Step 4. |
| 4. Observe the Readings in Cat ETA.Observe the status for “Engine Speed”, “Actual Injection Actuation Pressure” and “Engine Oil Pressure” on Cat ET while the engine is cranking. Record the following data: ·Engine Speed ·Actual injection actuation pressure ·Desired injection actuation pressure ·Engine oil pressure ·Fuel pressure ·Engine coolant temperature ·Observed “Injection Actuation Output Percent” | 100 rpm at 6 MPa (870 psi) | Results:The observed engine speed is above 100 rpm and the actual injection actuation pressure is at least 6 MPa (870 psi) while the engine is cranking.Repair:If a 94-11 code is active or logged, there is a problem with the fuel supply system. Refer to Testing and Adjusting, “Fuel System Pressure – Test” If a 94-11 code is not active or logged, refer to Test Step 5. Results:The observed engine speed is below 100 rpm. Repair:Refer to Troubleshooting, “Engines Cranks But Does Not Start”. STOP Results:The observed engine speed is above 100 rpm and the observed engine oil pressure is below 14 kPa (2 psi). STOP Results:The observed engine speed is above 100 rpm and the observed engine oil pressure is above 14 kPa (2 psi) and the actual injection actuation pressure is below 6 MPa (870 psi). Proceed to Test Step 7. |
Illustration 2 g01330859
Location of the connectors for the injector solenoids ( C7 engines)
(1) Connector at the valve cover
(2) J2/P2 ECM connectors
(3) Rubber grommet for the injector harness at the valve cover
Illustration 3 g01330939
Location of the connectors for the injector solenoids ( C9 engines)
(1) Connector at the valve cover
(2) J2/P2 ECM connectors
| Troubleshooting Test Steps | Values | Results |
| 1. Verify Communication Between the ECM and the Fuel Injectors A.Turn the key to the “OFF” position. An electrical shock hazard is present if the key is not in the “OFF” position. B.Disconnect the connector for the injector harness at the valve cover. Check for evidence of moisture in the connector. Refer to Troubleshooting, “Electrical Connectors – Inspect” for troubleshooting details. C.Crank the engine for 15 seconds. D.Check Cat ET for logged diagnostic codes that are related to the injector solenoids. | Fuel Injectors | Results:There are logged diagnostic codes for injector solenoids in all cylinders. The logged codes indicate communication between the ECM and the fuel injectors. Turn the key to the OFF position. Reconnect the connector for the injector harness. Clear all diagnostic codes. Proceed to Test Step 6. Results:At least one cylinder does not indicate a logged diagnostic code for the injector solenoid. Repair:There may be a problem with the engine harness or ECM. Record the numbers that do not indicate a logged diagnostic code for the injector solenoid. Turn the key to the OFF position. Reconnect the connector for the injector harness. Clear any diagnostic codes or event codes. Refer to Troubleshooting, “Injector Solenoid Circuit – Test”. STOP |
| 6. Check the Pressure of the Low Pressure Fuel System A.Observe the status for “Fuel Pressure” on Cat ET while the engine is cranking. Record the fuel pressure. | 175 kPa (25 psi) | Results:Observed fuel pressure is above 175 kPa (25 psi) while the engine is cranking. Repair:Access the “Injector Solenoid Test” in Cat ET. Activate the test. As each solenoid is energized by the ECM an audible click can be heard at the valve cover. Listen for a click at the valve cover. Cat ET will indicate the cylinder number as each solenoid is being energized. Replace injectors that do not produce an audible click. Verify the repair. If all injectors produce an audible click and the engine will not start, refer to Troubleshooting, “Engine Cranks but Will Not Start”. STOP Results:Observed fuel pressure is below Repair:There is a problem with the fuel supply system. Refer to System Operation, Test and Adjusting, “Fuel System Pressure – Test”. There is a problem with the fuel supply system. Refer to System Operation, Test and Adjusting, “Fuel System Pressure – Test”. |
| 7. Use a Test Lamp to Check for the Presence of Current A.Disconnect the J500/P500 IAPCV connector from the unit injector hydraulic pump. Note:Do not insert any wire that is larger than 18 AWG into the P500 harness connector. Do not insert the probe for the voltage test lamp into the P500 harness connector. These actions will spread the sockets of the connector which will damage the connector. Damaged connectors could cause intermittent connections. B.Insert a186-3735Connector Pin into each of the P500 harness connector sockets . C.Connect a voltage test lamp to the connector pins that are inserted in the P500 connector. D.Crank the engine and watch the test lamp. | Test lamp | Results:The test lamp illuminates while the engine is cranking. The ECM is operating correctly and the wiring harness to the pump is OK. Proceed to Test Step 8. Results:The test lamp does not illuminate while the engine is cranking. Repair:Refer to Troubleshooting, “Injection Actuation Pressure Control Valve Circuit – Test” for information on troubleshooting the circuit. STOP |
| Troubleshooting Test Steps | Values | Results |
| 8. Check the High Pressure Oil System for Leaks A.Remove the valve cover and inspect the high-pressure oil system for excessive oil leaks or discharge. B.Look at the injector bores for any signs of oil leakage while the engine is being cranked. Inspect the spill ports on the injectors for an excessive discharge of oil. All six injectors should discharge the same amount of oil. Excessive leakage or discharge can cause issues with the system pressure. C.Turn the key to the “OFF” position. An electrical shock hazard is present if the key is not turned to the “OFF” position. D.Disconnect the connector for the injector harness at the valve cover. Check for evidence of moisture in the connector. Refer to Troubleshooting, “Electrical Connectors – Inspect” for troubleshooting details. E.Crank the engine. Observe the injector bores for any signs of leakage. Inspect the spill ports on the injectors for an excessive discharge of oil. The injectors are now disabled and the injectors should discharge little oil, which is normal. Observe the status for the “Actual Injection Actuation Pressure” on Cat ET while the engine is cranking. F.Clear any diagnostic codes that are logged. | High Pressure Oil System | Results:There are no excessive oil leaks around injector bores. Also, there is no excessive discharge of oil from the spill ports of the injector. Repair:f the unit injector hydraulic pump has not been replaced during this procedure, replace the pump and repeat steps “E” and “F”. The engine will need to be cranked for a significant length of time in order to fill the pump with oil after the pump is replaced. Clear all diagnostic codes. If the unit injector hydraulic pump has been replaced during this procedure, and the actual injection actuation pressure was at least 6 MPa (870 psi) in Step “E”, proceed to Test Step 9. Results:If the unit injector hydraulic pump has already been replaced during this procedure and the actual injection actuation pressure was below Results:There are excessive oil leaks around the injector bores or excessive discharge of oil out of the spill port of the injector. Repair:Replace the O-ring on the injector(s) that is leaking around the bore(s) or replace the damaged injector(s) that is identified with excessive discharge out of the spill ports. Proceed to Test Step 9. |
| 9. Try to Start the Engine A.Turn the key to the “OFF” position. An electrical shock hazard is present if the key is not in the “OFF” position. C.Try to start the engine. Observe the status for “Actual Injection Actuation Pressure” on Cat ET while the engine is cranking. Record the actual injection actuation pressure. | Engine | Results:The engine starts. STOP Results:The engine does not start and actual injection actuation pressure is above Results:The engine does not start and actual injection actuation pressure is below Repair:If the unit injector hydraulic pump has not been replaced, replace the pump and try to start the engine. The engine will need to be cranked for a significant length of time in order to fill the pump with oil after the pump has been replaced. Clear all diagnostic codes. If the engine does not start, proceed to Test Step 5. Results:If the unit injector hydraulic pump has already been replaced in a previous test, stop and consult your local technical communicator for assistance. |
Extended oil drain intervals may cause elevated levels of soot in the engine oil. The elevated levels of soot may also deplete the additive package of the oil. This can affect the operation of the high-pressure oil system.
Refer to the engine’s Operation and Maintenance Manual for the recommended engine oil change interval and refill capacities.
| Troubleshooting Test Steps | Values | Results |
| 10. Check the Low Pressure Fuel and Oil System Pressures A.Start the engine. B.Observe the status for “Fuel Pressure” and “Engine Oil Pressure” on Cat ET while the engine is running. Record the following data: ·Observed fuel pressure from Cat ET ·Miles or Kilometers since the last oil change | Low Pressure Fuel and Oil System Pressures | Results:The customer has not exceeded the suggested oil change interval. Repair:Refer to Systems Operation, Testing and Adjusting, “Fuel System Pressure – Test” and Systems Operation/Testing and Adjusting If the problem still exists, proceed to Test Step 11. Results:The customer has exceeded the suggested oil change interval. Repair:If the customer has exceeded the suggested oil change interval, ask the customer to authorize an oil change with a new filter. Oil changes are not covered by the warranty. After the engine oil and the oil filter have been changed, operate the engine until normal operating temperature has been reached. Operate the engine at 1200 to 1500 rpm for 15 minutes. This will purge any trapped air or debris that is in the system. If the problem still exists, or if the problem reoccurs in a short period of time, repeat Test Step 10. |
| 11. Use “Injection Actuation Pressure Test” on Cat ET to Check the System A.Install the8T-0852Pressure Gauge in an accessible port in the high-pressure part of the injection actuation system. B.Start the engine. Note:The “Injection Actuation Pressure Test” can be used to increase the injection actuation pressure. Also, the “Injection Actuation Pressure Test” can be used to decrease the injection actuation pressure. The test adjusts the oil pressure of the injection actuation system in predefined steps. Step forward through all predefined steps in the test. Next, step backward through all predefined steps in the test. D.Record the pressure readings from the pressure gauge and from Cat ET in Table 5. | 1379 kPa (200 psi) | Results:The pressure that is measured with the pressure gauge for each step and the pressure that is displayed on Cat ET for each step are within 1379 kPa (200 psi). The injection actuation pressure sensor is operating properly. Repair:Do not replace the sensor. Proceed to Test Step 12. Results:he pressure that is measured with the pressure gauge for each step and the pressure that is displayed on Cat ET for each step are not within Repair:The injection actuation pressure sensor may be faulty. Replace the sensor and repeat this test step. If the problem still exists, verify the accuracy of the pressure gauge. Reinstall the original sensor and proceed to Test Step 12. |
| Step | Manual pressure gauge | Actual injection actuation pressure from Cat ET | Difference |
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
| 3 | |||
| 2 | |||
| 1 |
| Troubleshooting Test Steps | Values | Results |
| 12. Perform the “Injection Actuation Pressure Test” at Low Idle A. Start the engine. Run the “Injection Actuation Pressure Test” at low idle only. Step forward through all predefined steps in the test. Next, step backward through all the predefined steps in the test. Note:There may be a short lag in the reaction to the injection pressure. The pressure change should occur within two seconds of each command. B. Record the actual injection actuation pressure, the desired injection actuation pressure and the percent output from Cat ET in Table 7. | 1379 kPa (200 psi) | Results: The actual injection actuation pressure is no more than 1379 kPa (200 psi) above the desired injection actuation pressure for each step. Also, the actual injection actuation pressure does not fluctuate more than ±1000 kPa (±145 psi). Proceed to Test Step 13. Results: One of the actual injection actuation pressures is more than Repair: Replace the unit injector hydraulic pump. After the pump has been replaced, the engine will need to be cranked for a significant length of time in order to fill the pump with oil. Clear all diagnostic codes or event codes. Verify that the repair eliminates the problem. If the problem still exists, proceed to Test Step 13. |
| Low Idle | ||||
| Step | Actual injection actuation pressure from Cat ET (A) | Desired injection actuation pressure from Cat ET (B) | Difference (A-B) | Percent Output from Cat ET |
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 3 | ||||
| 2 | ||||
| 1 | ||||
| Troubleshooting Test Steps | Values | Results |
| 13. Check the High Pressure Oil System for Excessive Leaks A.Remove the valve cover and inspect the high-pressure oil system for excessive oil leaks or discharge. B.Start the engine and allow the engine to idle. Look at the injector bores for any signs of oil leakage. Inspect the spill ports on the injectors for an excessive discharge of oil. All six injectors should discharge the same amount of oil. Excessive leakage or discharge can cause issues with the system pressure. C.While the engine is at low idle, perform the “Injection Actuation Pressure Test” in Cat ET. Run the test at the highest pressure in order to maximize any possible leaks. Observe the status for “Actual Injection Actuation Pressure” on Cat ET. Record the following data: ·Any injectors with excessive leakage or discharge ·Actual injection actuation pressure at low idle D.Turn the key to the “OFF” position. An electrical shock hazard is present if the key is not turned to the “OFF” position. E.Disconnect the connector for the injector harness at the valve cover. Check for evidence of moisture in the connector. Refer to Troubleshooting, “Electrical Connectors – Inspect” for troubleshooting details. F.Crank the engine. Observe the injector bores for any signs of leakage. Inspect the spill ports on the injectors for an excessive discharge of oil. The injectors are now disabled and the injectors should discharge little oil, which is normal. ·Any injectors with excessive leakage or discharge ·Actual injection actuation pressure while the engine is cranking | Excessive discharge of oil | Results:There are no excessive oil leaks around injector bores. Also, there is no excessive discharge of oil from the spill ports of the injector. Proceed to Test Step 14. Results:There are excessive oil leaks around injector bores or there is an excessive discharge of oil from the spill ports of the injector. Repair:Replace the O-ring on the injector(s) that is leaking around the bore(s) or replace the damaged injector(s) that is identified with excessive discharge out of the spill ports. Verify that the repair eliminates the problem. If the problem remains after the repair, proceed to Test Step 14. |
