LaCrosse FWD V6-3.0L (2010)
3. Engine idling at normal operating temperature, verify the scan tool Fuel Pump Control Module Fuel Pressure Sensor parameter is between
276-324 kPa (40-47 psi).
Circuit/System Testing
Note:
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The Fuel Pump Enable may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
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DO NOT start the engine.
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High fuel pressure readings may result due to hot soak fuel boiling. With the engine OFF, the fuel pressure may increase to the setting of the
pressure relief regulator valve, approximately 580 kPa (84 psi).
1. Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool and observe the fuel pressure gauge while the fuel pump is
operating. Verify the fuel pressure is between 276-448 kPa (40-65 psi).
‹› If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the fuel
pump module.
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Restricted fuel feed pipe
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Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
2. Verify that the fuel pressure does not decrease greater than 34 kPa (5 psi) in 1 min.
‹› If the fuel pressure decreases greater than the specified value, perform the following procedure:
1. Ignition OFF, relieve the fuel pressure. Refer to Fuel Pressure Relief (See: Fuel Filter/Fuel Pressure Release/Service and Repair).
2. Disconnect the chassis fuel feed hose from the engine compartment fuel pipe.
3. Install the J 37287 - Adapter between the chassis fuel hose and the engine compartment fuel pipe.
4. Open the valve on the J 37287 - Adapter.
5. Ignition ON, command the Fuel Pump Enable ON with a scan tool and bleed the air from the CH-48027 - Gauge.
6. Command the Fuel Pump Enable ON with a scan tool.
7. Close the valve on the J 37287 - Adapter.
8. Monitor the fuel pressure for 1 min.
‹› If the fuel pressure does not decrease greater than 34 kPa (5 psi) within the specified time, replace the fuel pump module.
3. Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease greater than 14 kPa (2 psi) in 5 min.
‹› If the fuel pressure decreases greater than the specified value, replace the fuel pump module.
4. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH-48027 - Gauge. The fuel
pressure should not drop off during acceleration, cruise, or hard cornering.
‹› If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module.
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Restricted fuel feed pipe
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Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
5. If the fuel system tests normal, refer to Symptoms - Engine Controls (See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Controls).
Repair Instructions
Perform the Diagnostic Repair Verification (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Diagnostic Trouble
Code Tests and Associated Procedures/Verification Tests and Procedures) after completing the diagnostic procedure.
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Fuel Feed Pipe Replacement (LLT) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Supply Line/Service and Repair/Fuel
Feed Pipe Replacement)Fuel Feed Pipe Replacement (LF1) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Supply
Line/Service and Repair/Fuel Feed Pipe Replacement)
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Fuel Pump Fuel Feed Hose Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service and Repair/Fuel
Pump Fuel Feed Hose Replacement)
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Fuel Tank Fuel Pump Module Replacement (NT7) (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service and
Repair/Fuel Tank Fuel Pump Module Replacement (NT7))Fuel Tank Fuel Pump Module Replacement (NU6) (See: Powertrain
Management/Fuel Delivery and Air Induction/Fuel Pump/Service and Repair/Fuel Tank Fuel Pump Module Replacement (NU6))
