Tahoe 2WD V8-6.0L Hybrid (2008)
Important: 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.
1. Verify that the fuel pressure does not decrease more than 34 kPa (5 psi) in 1 minute.
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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 (With CH 48027) Fuel Pressure Relief (Without CH 48027).
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 gage.
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.
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If the fuel pressure drops, locate and replace the leaking fuel injector.
7. If the fuel system test normal, replace the fuel pump.
2. 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.
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If the fuel pressure decreases more than the specified value, replace the fuel pump.
3. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH-48027. The fuel pressure
should not drop off during accelerations, cruise or hard cornering.
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If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module.
4. If the fuel system components test normal, refer to Symptoms - Computers and Control Systems.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Computers and Control Systems/Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
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Fuel Injector Replacement
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Fuel Tank Fuel Pump Module Replacement
