Diagnostic Aids

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.

Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same Freeze Frame conditions (RPM, engine load, vehicle speed, temperature, etc.). This will isolate when the DTC failed.

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

DTC P2066 (5.3L Engine)

Step	Action	Yes	No
Schematic Reference: Instrument Cluster Schematics
1	Did you perform the Instrument Cluster Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - Instrument Cluster
2	Remove the fuel level sender. Inspect for the following items: A stuck fuel level sender, i.e. the fuel strainer interfering with the sender float arm Foreign material in the fuel tank, i.e. ice Did you find and correct the condition?	Go to Step 4	Go to Step 3
3	Replace the fuel level sender. Refer to Fuel Level Sensor Replacement (4.8L, 5.3L, and 6.0L Engines) or Fuel Level Sensor Replacement (5.3L (L59) Engine) in Engine Controls - 4.8L, 5.3L and 6.0L. Did you complete the replacement?	Go to Step 4	-
4	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	Go to Step 2	System OK