C7 and C9 Industrial Engines Caterpillar

Use the steps that follow to check the operation of the HEUI fuel system or troubleshoot a 164-11 Injector Actuation Pressure : Other Failure Mode diagnostic code. 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

Table 1

Troubleshooting Test Steps	Values	Results
1. Check for Codes A. 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 Engine A. 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 Sensor A. 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 ET A. 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). Repair: There is a problem with the engine oil supply. Refer to Testing and Adjusting, "Engine Oil Pressure - Test". 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.

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Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

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

Table 2

Troubleshooting Test Steps	Values	Results
5. 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 175 kPa (25 psi) while the engine is cranking. 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 a 186-3735 Connector 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

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Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

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Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

Table 3

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 6 MPa (870 psi) in Step "E", consult your local technical communicator for assistance. 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. B. Reconnect the connector for the injector harness at the valve cover and install the valve cover. 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 6 MPa (870 psi). Proceed to Test Step 5. Results: The engine does not start and actual injection actuation pressure is below 6 MPa (870 psi). 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.

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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

Table 4

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 · Observed engine oil pressure from Cat ET · Drain interval · 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 , "Engine Oil Pressure - Test" in order to verify that the observed fuel pressure and engine oil pressures are acceptable. If a 94-1 diagnostic code is active or if a 94-1 diagnostic code is logged, a problem in the fuel supply system has occurred. Refer to Systems Operation, Testing and Adjusting, "Fuel System Pressure - Test". Make necessary repairs. Verify that the repair eliminates the problem. 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 the 8T-0852 Pressure Gauge in an accessible port in the high-pressure part of the injection actuation system. B. Start the engine. C. Access the "Injection Actuation Pressure Test" in the "Diagnostics Menu" of Cat ET and begin the test. 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 1379 kPa (200 psi). 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.

Table 5

Step	Manual pressure gauge	Actual injection actuation pressure from Cat ET	Difference
1
2
3
4
3
2
1

Table 6

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 1379 kPa (200 psi) above the desired injection actuation pressure on at least one step, or the actual injection actuation pressure fluctuates more than ±1000 kPa (±145 psi) 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.

Table 7

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

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Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

Table 8

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. G. While the engine is cranking, 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 while the engine is cranking H. Clear any diagnostic codes that are logged.	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.

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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

Table 9

Troubleshooting Test Steps	Values	Results
14. Check the Oil Pressure at the Pump (High Pressure Pump Test) A. Turn the key to the "OFF" position. B. Reconnect the connector for the injector harness at the valve cover and install the valve cover. C. Install the 8T-0852 Pressure Gauge in an accessible port in the high-pressure portion of the injection actuation system. D. Disconnect the connector for the injection actuation pressure sensor and plug a spare injection actuation pressure sensor into the engine harness. Allow the spare sensor to hang on the side of the engine. Note: This configuration allows the unit injector hydraulic pump to build maximum pressure. The engine will not start in this configuration. E. Install a 224-9282 Adapter Cable As in series with the P500 connector. Reconnect the P500/J500 connector. Note: There must be a continuous electrical connection between the ECM and the unit injector hydraulic pump. The improper connection or the incomplete connection of the adapter cable may provide incorrect results. F. Connect a multimeter that is capable of measuring current that is 0 to 1,000 milliampere in series with the adapter cable. Select the lowest current range for the multimeter that is greater than one amp. Note: If the multimeter is not set to the correct scale, the following measurement may provide misleading results. G. Crank the engine and record the following data: · Observed pressure reading from the pressure gauge Note: If the gauge fluctuates use the average. · Observed engine speed from Cat ET · Observed "Injection Actuation Output Percent" from Cat ET · Current reading from the multimeter	29.5 MPa (4278 psi) and the current is above 400 mA	Results: The oil pressure is above 29.5 MPa (4278 psi) and the current is above 400 mA. Leave the system in the present configuration and proceed to Test Step 15. Results: The oil pressure is below 29.5 MPa (4278 psi) and the current is above 400 mA. Repair: Replace the unit injector hydraulic pump. If the drive gear on the pump is loose, do not attempt to tighten the drive gear and reuse the 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, consult your local technical communicator for assistance. STOP Results: The current is below 400 mA. Repair: Refer to Troubleshooting, "Injection Actuation Pressure Control Valve - Test". STOP
15. Use the "Cylinder Cutout Test" on Cat ET to Check the Fuel Injectors The troubleshooting indicates that the unit injector hydraulic pump is working properly. Record the following data: · Engine symptoms (misfire, excessive smoke, low power, runs rough) · Conditions when the engine symptom occurs, (high load, idle, cold start, acceleration, etc) · The frequency of the engine symptoms (intermittent, constant, etc) A. Perform a cylinder cutout procedure if the test has not already been performed or if any other repairs have been completed since the most recent cylinder cutout procedure. Refer to Troubleshooting, "Injector Solenoid Circuit - Test" for troubleshooting details.	Injector Operation	Results: The injectors are operating properly according to the "Injector Solenoid Circuit - Test". Also, the engine symptoms are still present. Repair: Consult your local technical communicator for assistance. STOP Results: The"Injector Solenoid Circuit - Test" indicates faulty injectors. Repair: Replace the faulty injectors. Verify that the repair eliminates the problem. If the problem still exists, consult your local technical communicator for assistance.