Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step tests for a fuel heater thermostatic switch that is stuck ON.
- 3: This steps tests for a thermostatic switch that completes the circuit.
Fuel Heater Always On
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics | ||||
| 1 | Does the Water In Fuel lamp operate properly? | - | Go to Step 2 | Go to Water-in-Fuel Lamp Always On in Instrument Panel, Gages, and Console |
| 2 |
|
- | Go to Step 3 | Go to Step 4 |
| 3 |
IMPORTANT:
The fuel filter/heater element housing must be cooled to below 8°C (46°F) before the thermostatic switch will turn ON.
|
8-15°C (46-59°F) | Go to Step 5 | Go to Step 4 |
| 4 | Replace the fuel filter/heater element housing. Refer to Fuel Filter/Heater Element Housing Replacement
. Did you complete the replacement? |
- | Go to Step 5 | - |
| 5 | Operate the vehicle under which the condition was noted. Does the system operate properly? |
- | System OK | Go to Step 1 |