Yukon XL 4WD V8-5.3L (2011)
fuel pressure is between 345-414 kPa (50-60 psi).
‹› If the fuel pressure is greater than the specified range, replace the fuel pump.
‹› If the fuel pressure is less than the specified range, remove the fuel tank and test, inspect, and repair the items listed below. If all items test
normal, replace the fuel tank fuel pump module.
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Restricted fuel feed pipe
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Restricted or plugged fuel filter
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Restricted or plugged strainer
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Stuck or binding fuel level float
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Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
Note: The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should
stabilize and remain constant.
2. Verify that the fuel pressure does not decrease more than 34 kPa (5 psi) in 1 minute.
‹› If the fuel pressure decreases more than the specified value, perform the following procedure:
1. Ignition OFF, relieve the fuel pressure. Refer to Fuel Pressure Relief .
2. Install the J 37287 between the fuel feed pipe and the fuel rail.
3. Open the valve on the J 37287 .
4. Ignition ON, command the Fuel Pump Relay ON with a scan tool and bleed the air from the fuel pressure gauge.
5. Close the valve on the J 37287 .
6. Verify that the fuel pressure does not decrease more than 34 kPa (5 psi) in 1 minute.
‹› If the fuel pressure drops, locate and replace the leaking fuel injector.
7. If the fuel system test normal, replace the fuel tank fuel pump module.
3. Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease more than 14 kPa (2 psi) in 5 minutes.
‹› If the fuel pressure decreases more than the specified value, replace the fuel tank fuel pump module.
4. Remove the J 37287 and CH-48027 . Refer to Fuel Pressure Gauge Installation and Removal See: Fuel Pressure Gauge Installation and
Removal.
5. Operate the vehicle within the conditions of the customers concern while monitoring the fuel trim and HO2S parameters with a scan tool. The scan
tool parameters should not indicate a lean condition.
‹› If the scan tool parameters indicate a lean condition, test for a restricted fuel feed pipe, restricted fuel filter, or poor connections at the harness
connectors and ground circuits of the fuel pump. If all test normal, replace the fuel tank fuel pump module.
6. If the fuel system components test 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 Injector Replacement See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Removal and
Replacement
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Fuel Tank Fuel Pump Module Replacement