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Circuit/System Testing

WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Check the Water in Fuel lamp for proper operation. Refer to Water-in-Fuel Lamp Always On .

  1. Turn ON the ignition, with the engine OFF.
  2. Disconnect the fuel heater connector.
  3. With the fuel temperature above 21°C (70°F), test for continuity between the ignition 1 voltage terminal and the fuel filter/heater element housing.
    • If continuity was present, the thermostatic switch is stuck ON. Replace the fuel filter/heater element housing.
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