‹

Fuel Pressure

Powertrain Management › Tune-up and Engine Performance Checks
Unified entry — merged from multiple cross-listed pages in the original manual.
Procedures
Fuel Pressure: Specificationsreference
Fig. 1
Fig. 1
FUEL PRESSURE Fuel pressure 407 KPa ± 34 KPa (59 psi ± 5 psi). Note: Ignition on, engine not running. VOLUME Measure the amount of fuel in the Reservoir Assembly. The fuel output specification is ml/s x 20 seconds = fuel flow in ml.
Fuel Pressure Leak Down12 steps
⚠ WARNING
Follow these safety precautions to reduce the risk of fire and serious possible serious or fatal injury when performing this test procedure.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
To reduce the risk of fire and serious possible serious or fatal injury, place Reservoir Assembly 534960 (4) on the floor and out of the way so that it is not a trip hazard.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
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  1. Visually and physically inspect the fuel delivery system for external leaks and damage. Is the system leaking or damaged? Yes -Repair / replace as necessary. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -Go To 2 2. INSTALL APPROPRIATE FUEL LINE ADAPTERS / FITTING FROM GAS AND DIESEL FUEL PRESSURE/DECAY TESTER 8978A
  2. Turn the ignition off.
  3. Disconnect the frame rail fuel supply line connector between the fuel supply line and the fuel rail.
  4. Install the appropriate Fuel Line Adapters / Fitting from Gas and Diesel Fuel Pressure/Decay Tester. Proceed -Go To 3 3. INSTALL FUEL PRESSURE GAUGE ASSEMBLY
  5. Connect Fuel Pressure Gauge Assembly Fuel Inlet Hose (1) and Fuel Outlet Hose (2) to the Fuel Line Adapters / Fitting.
  6. Connect Drain Extension Hose 535680 (3) to the Fuel Pressure Gauge Assembly Drain Hose (5).
  7. Connect the Reservoir Assembly 534960 (4) to the Drain Extension Hose 535680 (3). Proceed -Go To 4 4. CHECK FUEL PRESSURE
  8. Perform the following procedure to purge air from the system: -Open the Fuel System Isolation Valve (1). -Close the Flow Test Valve (2). -Ignition on, engine not running. -With the scan tool, actuate the fuel pump. -Open the Flow Test Valve (1) for 10 seconds, then close the Valve. -CAUTION: Stop All Actuations. -Turn the ignition off. -Disconnect, empty and then reconnect the Reservoir Assembly.
  9. Turn the ignition on, wait five seconds, turn the ignition off and then wait 1 minute before proceeding.
  10. Read the Fuel Pressure Gauge (3) and record the reading. Non SRT-4 fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi). SRT-4 fuel pressure specification is 552 KPa +/- 34 KPa (80 psi +/- 5 psi). Is the fuel pressure within specifications? Yes -Go To 5 No -Perform the Checking The Fuel Delivery System diagnostic procedure as directed. 5. CHECK FUEL DELIVERY SYSTEM FOR LEAK DOWN
  11. Close the Fuel System Isolation Valve (1) and then wait five minutes before proceeding.
  12. Read the Fuel Inlet (2) and Fuel Outlet (3) Pressure Gauges. The pressure should not drop more than 10 psi on either gauge. Does the fuel pressure drop more than 10 psi? Yes - On Fuel Inlet Gauge (1) -Replace the fuel pump module. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. Yes - On Fuel Outlet Gauge (2) -Replace the leaking fuel injector(s). -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -If directed here by another test, return to that test. Otherwise, test complete.
Checking The Fuel Delivery System35 steps
ℹ NOTE
It may be necessary to use a mechanics stethoscope in the next step.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure even with the engine off. Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
△ CAUTION
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box to perform diagnosis.
ℹ NOTE
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
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  1. Ignition on, engine not running.
  2. With a scan tool, actuate the Fuel System test.
  3. Listen for fuel pump operation at the fuel tank. Does the Fuel Pump operate? Yes -Go To 2 No -Go To 5 CAUTION: Stop All Actuations. 2. FUEL PRESSURE
  4. Turn the ignition off.
  5. Install a fuel pressure gauge at the engine.
  6. Ignition on, engine not running.
  7. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Choose a conclusion that best matches your fuel pressure reading. Below Specification -Go To 3 Within Specification -Check for contamination/water in the fuel. Make sure the fuel being used in this vehicle meets manufactures Fuel Requirement. Above Specification -Replace the fuel filter/fuel pressure regulator. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. CAUTION: Stop All Actuations. 3. RESTRICTED FUEL SUPPLY LINE
  8. Turn the ignition off.
  9. Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
  10. Install special tool # (5/16") or #(3/8") fuel line adapter and the fuel pressure gauge between the fuel supply line and the fuel pump module.
  11. Ignition on, engine not running.
  12. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Is the fuel pressure within specification now? Yes -Repair/replace fuel supply line as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 4 CAUTION: Stop All Actuations. 4. CHECKING FUEL INLET STRAINER
  13. Turn the ignition off.
  14. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Is the Fuel Inlet Strainer plugged? Yes -Replace the Fuel Pump Inlet Strainer. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Fuel Pump Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 5. FUEL PUMP CONTROL OPERATION FROM THE PCM
  15. Stop the Fuel Pump actuation.
  16. Turn the ignition off.
  17. Disconnect the C1 TIPM harness connector.
  18. Ignition on, engine not running.
  19. Using a 12-volt test light connected to B+ probe the (K31 Fuel Pump Control circuit in the C1 TIPM harness connector.
  20. Using a scan tool actuate the Fuel Pump under the PCM actuations. Does the test light illuminate brightly during the actuation? Yes -Go To 8 No -Go To 6 6. (K31) FUEL PUMP CONTROL CIRCUIT OPEN
  21. Turn the ignition off.
  22. Disconnect the C3 PCM harness connector.
  23. Measure the resistance of the (K31) Fuel Pump Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #. Is the resistance below 5.0 ohms? Yes -Go To 7 No -Repair the open in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 7. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
  24. Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM C1 harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 11 8. (N1) FUEL PUMP OUTPUT CIRCUIT OPEN
  25. Turn the ignition off.
  26. Disconnect the C5 TIPM harness connector.
  27. Disconnect the Fuel Pump Module harness connector.
  28. Measure the resistance of the (N1) Fused Fuel Pump Output circuit from the C5 TIPM harness connector and the Fuel Pump Module harness connector. Is the resistance above 5.0 ohms? Yes -Repair the open in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 9 9. (N1) FUEL PUMP OUTPUT CIRCUIT SHORTED TO GROUND
  29. Measure the resistance between ground and the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 10 10. FUEL PUMP MODULE/TIPM
  30. Connect the C3 PCM harness connector.
  31. Connect the C1 and C5 TIPM harness connectors.
  32. Turn the ignition on.
  33. Using a scan tool actuate the Fuel Pump Module.
  34. Using a 12-volt test light connected to ground, probe the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Does the test light illuminate? Yes -Replace the Fuel Pump Module. Fuel Tank - Removal. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Totally Integrated Power Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 11. POWERTRAIN CONTROL MODULE (PCM)
  35. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes -Repair as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace and program the Powertrain Control Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
Fuel Pressure: Specificationsreference
Fig. 1
Fig. 1
FUEL PRESSURE Fuel pressure 407 KPa ± 34 KPa (59 psi ± 5 psi). Note: Ignition on, engine not running. VOLUME Measure the amount of fuel in the Reservoir Assembly. The fuel output specification is ml/s x 20 seconds = fuel flow in ml.
Fuel Pressure Leak Down12 steps
⚠ WARNING
Follow these safety precautions to reduce the risk of fire and serious possible serious or fatal injury when performing this test procedure.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
To reduce the risk of fire and serious possible serious or fatal injury, place Reservoir Assembly 534960 (4) on the floor and out of the way so that it is not a trip hazard.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
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  1. Visually and physically inspect the fuel delivery system for external leaks and damage. Is the system leaking or damaged? Yes -Repair / replace as necessary. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -Go To 2 2. INSTALL APPROPRIATE FUEL LINE ADAPTERS / FITTING FROM GAS AND DIESEL FUEL PRESSURE/DECAY TESTER 8978A
  2. Turn the ignition off.
  3. Disconnect the frame rail fuel supply line connector between the fuel supply line and the fuel rail.
  4. Install the appropriate Fuel Line Adapters / Fitting from Gas and Diesel Fuel Pressure/Decay Tester. Proceed -Go To 3 3. INSTALL FUEL PRESSURE GAUGE ASSEMBLY
  5. Connect Fuel Pressure Gauge Assembly Fuel Inlet Hose (1) and Fuel Outlet Hose (2) to the Fuel Line Adapters / Fitting.
  6. Connect Drain Extension Hose 535680 (3) to the Fuel Pressure Gauge Assembly Drain Hose (5).
  7. Connect the Reservoir Assembly 534960 (4) to the Drain Extension Hose 535680 (3). Proceed -Go To 4 4. CHECK FUEL PRESSURE
  8. Perform the following procedure to purge air from the system: -Open the Fuel System Isolation Valve (1). -Close the Flow Test Valve (2). -Ignition on, engine not running. -With the scan tool, actuate the fuel pump. -Open the Flow Test Valve (1) for 10 seconds, then close the Valve. -CAUTION: Stop All Actuations. -Turn the ignition off. -Disconnect, empty and then reconnect the Reservoir Assembly.
  9. Turn the ignition on, wait five seconds, turn the ignition off and then wait 1 minute before proceeding.
  10. Read the Fuel Pressure Gauge (3) and record the reading. Non SRT-4 fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi). SRT-4 fuel pressure specification is 552 KPa +/- 34 KPa (80 psi +/- 5 psi). Is the fuel pressure within specifications? Yes -Go To 5 No -Perform the Checking The Fuel Delivery System diagnostic procedure as directed. 5. CHECK FUEL DELIVERY SYSTEM FOR LEAK DOWN
  11. Close the Fuel System Isolation Valve (1) and then wait five minutes before proceeding.
  12. Read the Fuel Inlet (2) and Fuel Outlet (3) Pressure Gauges. The pressure should not drop more than 10 psi on either gauge. Does the fuel pressure drop more than 10 psi? Yes - On Fuel Inlet Gauge (1) -Replace the fuel pump module. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. Yes - On Fuel Outlet Gauge (2) -Replace the leaking fuel injector(s). -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -If directed here by another test, return to that test. Otherwise, test complete.
Checking The Fuel Delivery System35 steps
ℹ NOTE
It may be necessary to use a mechanics stethoscope in the next step.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure even with the engine off. Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
△ CAUTION
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box to perform diagnosis.
ℹ NOTE
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
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  1. Ignition on, engine not running.
  2. With a scan tool, actuate the Fuel System test.
  3. Listen for fuel pump operation at the fuel tank. Does the Fuel Pump operate? Yes -Go To 2 No -Go To 5 CAUTION: Stop All Actuations. 2. FUEL PRESSURE
  4. Turn the ignition off.
  5. Install a fuel pressure gauge at the engine.
  6. Ignition on, engine not running.
  7. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Choose a conclusion that best matches your fuel pressure reading. Below Specification -Go To 3 Within Specification -Check for contamination/water in the fuel. Make sure the fuel being used in this vehicle meets manufactures Fuel Requirement. Above Specification -Replace the fuel filter/fuel pressure regulator. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. CAUTION: Stop All Actuations. 3. RESTRICTED FUEL SUPPLY LINE
  8. Turn the ignition off.
  9. Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
  10. Install special tool # (5/16") or #(3/8") fuel line adapter and the fuel pressure gauge between the fuel supply line and the fuel pump module.
  11. Ignition on, engine not running.
  12. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Is the fuel pressure within specification now? Yes -Repair/replace fuel supply line as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 4 CAUTION: Stop All Actuations. 4. CHECKING FUEL INLET STRAINER
  13. Turn the ignition off.
  14. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Is the Fuel Inlet Strainer plugged? Yes -Replace the Fuel Pump Inlet Strainer. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Fuel Pump Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 5. FUEL PUMP CONTROL OPERATION FROM THE PCM
  15. Stop the Fuel Pump actuation.
  16. Turn the ignition off.
  17. Disconnect the C1 TIPM harness connector.
  18. Ignition on, engine not running.
  19. Using a 12-volt test light connected to B+ probe the (K31 Fuel Pump Control circuit in the C1 TIPM harness connector.
  20. Using a scan tool actuate the Fuel Pump under the PCM actuations. Does the test light illuminate brightly during the actuation? Yes -Go To 8 No -Go To 6 6. (K31) FUEL PUMP CONTROL CIRCUIT OPEN
  21. Turn the ignition off.
  22. Disconnect the C3 PCM harness connector.
  23. Measure the resistance of the (K31) Fuel Pump Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #. Is the resistance below 5.0 ohms? Yes -Go To 7 No -Repair the open in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 7. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
  24. Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM C1 harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 11 8. (N1) FUEL PUMP OUTPUT CIRCUIT OPEN
  25. Turn the ignition off.
  26. Disconnect the C5 TIPM harness connector.
  27. Disconnect the Fuel Pump Module harness connector.
  28. Measure the resistance of the (N1) Fused Fuel Pump Output circuit from the C5 TIPM harness connector and the Fuel Pump Module harness connector. Is the resistance above 5.0 ohms? Yes -Repair the open in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 9 9. (N1) FUEL PUMP OUTPUT CIRCUIT SHORTED TO GROUND
  29. Measure the resistance between ground and the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 10 10. FUEL PUMP MODULE/TIPM
  30. Connect the C3 PCM harness connector.
  31. Connect the C1 and C5 TIPM harness connectors.
  32. Turn the ignition on.
  33. Using a scan tool actuate the Fuel Pump Module.
  34. Using a 12-volt test light connected to ground, probe the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Does the test light illuminate? Yes -Replace the Fuel Pump Module. Fuel Tank - Removal. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Totally Integrated Power Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 11. POWERTRAIN CONTROL MODULE (PCM)
  35. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes -Repair as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace and program the Powertrain Control Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
Fuel Pressure: Specificationsreference
Fig. 1
Fig. 1
FUEL PRESSURE Fuel pressure 407 KPa ± 34 KPa (59 psi ± 5 psi). Note: Ignition on, engine not running. VOLUME Measure the amount of fuel in the Reservoir Assembly. The fuel output specification is ml/s x 20 seconds = fuel flow in ml.
Fuel Pressure Leak Down12 steps
⚠ WARNING
Follow these safety precautions to reduce the risk of fire and serious possible serious or fatal injury when performing this test procedure.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
To reduce the risk of fire and serious possible serious or fatal injury, place Reservoir Assembly 534960 (4) on the floor and out of the way so that it is not a trip hazard.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting, or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
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  1. Visually and physically inspect the fuel delivery system for external leaks and damage. Is the system leaking or damaged? Yes -Repair / replace as necessary. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -Go To 2 2. INSTALL APPROPRIATE FUEL LINE ADAPTERS / FITTING FROM GAS AND DIESEL FUEL PRESSURE/DECAY TESTER 8978A
  2. Turn the ignition off.
  3. Disconnect the frame rail fuel supply line connector between the fuel supply line and the fuel rail.
  4. Install the appropriate Fuel Line Adapters / Fitting from Gas and Diesel Fuel Pressure/Decay Tester. Proceed -Go To 3 3. INSTALL FUEL PRESSURE GAUGE ASSEMBLY
  5. Connect Fuel Pressure Gauge Assembly Fuel Inlet Hose (1) and Fuel Outlet Hose (2) to the Fuel Line Adapters / Fitting.
  6. Connect Drain Extension Hose 535680 (3) to the Fuel Pressure Gauge Assembly Drain Hose (5).
  7. Connect the Reservoir Assembly 534960 (4) to the Drain Extension Hose 535680 (3). Proceed -Go To 4 4. CHECK FUEL PRESSURE
  8. Perform the following procedure to purge air from the system: -Open the Fuel System Isolation Valve (1). -Close the Flow Test Valve (2). -Ignition on, engine not running. -With the scan tool, actuate the fuel pump. -Open the Flow Test Valve (1) for 10 seconds, then close the Valve. -CAUTION: Stop All Actuations. -Turn the ignition off. -Disconnect, empty and then reconnect the Reservoir Assembly.
  9. Turn the ignition on, wait five seconds, turn the ignition off and then wait 1 minute before proceeding.
  10. Read the Fuel Pressure Gauge (3) and record the reading. Non SRT-4 fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi). SRT-4 fuel pressure specification is 552 KPa +/- 34 KPa (80 psi +/- 5 psi). Is the fuel pressure within specifications? Yes -Go To 5 No -Perform the Checking The Fuel Delivery System diagnostic procedure as directed. 5. CHECK FUEL DELIVERY SYSTEM FOR LEAK DOWN
  11. Close the Fuel System Isolation Valve (1) and then wait five minutes before proceeding.
  12. Read the Fuel Inlet (2) and Fuel Outlet (3) Pressure Gauges. The pressure should not drop more than 10 psi on either gauge. Does the fuel pressure drop more than 10 psi? Yes - On Fuel Inlet Gauge (1) -Replace the fuel pump module. -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. Yes - On Fuel Outlet Gauge (2) -Replace the leaking fuel injector(s). -Perform the PCM VERIFICATION TEST. Powertrain Verification Test. No -If directed here by another test, return to that test. Otherwise, test complete.
Checking The Fuel Delivery System35 steps
ℹ NOTE
It may be necessary to use a mechanics stethoscope in the next step.
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure even with the engine off. Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.
ℹ NOTE
Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
⚠ WARNING
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
ℹ NOTE
Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
△ CAUTION
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box to perform diagnosis.
ℹ NOTE
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
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  1. Ignition on, engine not running.
  2. With a scan tool, actuate the Fuel System test.
  3. Listen for fuel pump operation at the fuel tank. Does the Fuel Pump operate? Yes -Go To 2 No -Go To 5 CAUTION: Stop All Actuations. 2. FUEL PRESSURE
  4. Turn the ignition off.
  5. Install a fuel pressure gauge at the engine.
  6. Ignition on, engine not running.
  7. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Choose a conclusion that best matches your fuel pressure reading. Below Specification -Go To 3 Within Specification -Check for contamination/water in the fuel. Make sure the fuel being used in this vehicle meets manufactures Fuel Requirement. Above Specification -Replace the fuel filter/fuel pressure regulator. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. CAUTION: Stop All Actuations. 3. RESTRICTED FUEL SUPPLY LINE
  8. Turn the ignition off.
  9. Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
  10. Install special tool # (5/16") or #(3/8") fuel line adapter and the fuel pressure gauge between the fuel supply line and the fuel pump module.
  11. Ignition on, engine not running.
  12. With the scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge. Is the fuel pressure within specification now? Yes -Repair/replace fuel supply line as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 4 CAUTION: Stop All Actuations. 4. CHECKING FUEL INLET STRAINER
  13. Turn the ignition off.
  14. Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer. Is the Fuel Inlet Strainer plugged? Yes -Replace the Fuel Pump Inlet Strainer. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Fuel Pump Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 5. FUEL PUMP CONTROL OPERATION FROM THE PCM
  15. Stop the Fuel Pump actuation.
  16. Turn the ignition off.
  17. Disconnect the C1 TIPM harness connector.
  18. Ignition on, engine not running.
  19. Using a 12-volt test light connected to B+ probe the (K31 Fuel Pump Control circuit in the C1 TIPM harness connector.
  20. Using a scan tool actuate the Fuel Pump under the PCM actuations. Does the test light illuminate brightly during the actuation? Yes -Go To 8 No -Go To 6 6. (K31) FUEL PUMP CONTROL CIRCUIT OPEN
  21. Turn the ignition off.
  22. Disconnect the C3 PCM harness connector.
  23. Measure the resistance of the (K31) Fuel Pump Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #. Is the resistance below 5.0 ohms? Yes -Go To 7 No -Repair the open in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 7. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
  24. Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM C1 harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (K31) Fuel Pump Control circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 11 8. (N1) FUEL PUMP OUTPUT CIRCUIT OPEN
  25. Turn the ignition off.
  26. Disconnect the C5 TIPM harness connector.
  27. Disconnect the Fuel Pump Module harness connector.
  28. Measure the resistance of the (N1) Fused Fuel Pump Output circuit from the C5 TIPM harness connector and the Fuel Pump Module harness connector. Is the resistance above 5.0 ohms? Yes -Repair the open in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 9 9. (N1) FUEL PUMP OUTPUT CIRCUIT SHORTED TO GROUND
  29. Measure the resistance between ground and the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Is the resistance below 100 ohms? Yes -Repair the short to ground in the (N1) Fused Fuel Pump Output circuit. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Go To 10 10. FUEL PUMP MODULE/TIPM
  30. Connect the C3 PCM harness connector.
  31. Connect the C1 and C5 TIPM harness connectors.
  32. Turn the ignition on.
  33. Using a scan tool actuate the Fuel Pump Module.
  34. Using a 12-volt test light connected to ground, probe the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector. Does the test light illuminate? Yes -Replace the Fuel Pump Module. Fuel Tank - Removal. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace the Totally Integrated Power Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. 11. POWERTRAIN CONTROL MODULE (PCM)
  35. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits. Were there any problems found? Yes -Repair as necessary. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test. No -Replace and program the Powertrain Control Module. -Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
Factory service manual
From the 2008 KK factory manual — descriptions, specs, torque & procedures for this part.
FUEL SYSTEM PRESSURE📷 3
400 kPa +/- 34 kPa (58 psi +/- 5 psi).
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