SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2006SUBURBAN C2500, 6.0 UREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1779 (ENGINE CONTROL SYSTEM & FUEL SYSTEM - 4.8L, 5.3L, 6.0L, 6.2L - TROUBLESHOOTING AND DIAGNOSIS)FUEL SYSTEM DIAGNOSIS (WITHOUT FPCM)CIRCUIT/SYSTEM TESTING
2006 Chevrolet Suburban C2500, 6.0 U

Circuit/System Testing

2006 Chevrolet Suburban C2500, 6.0 USECTION Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
    IMPORTANT:
    • The fuel pump relay may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
    • DO NOT start the engine.
  1. Ignition ON, command the fuel pump relay ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the 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 pump.
      • Restricted fuel feed pipe
      • Restricted or plugged fuel filter
      • Restricted or plugged strainer
      • Stuck or binding fuel level float
      • Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
    2. 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.
  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 (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 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 pump.
  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 pump.
  4. Remove the J 37287  and CH-48027  . Refer to Fuel Pressure Gauge Installation and Removal .
  5. Operate the vehicle within the conditions of the customers concern while monitoring the fuel trim and O2 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 pump.
  6. If the fuel system components test normal, refer to Symptoms - Engine Controls .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.