K 3500 Truck 4WD V8-6.6L DSL Turbo VIN 1 (2001)
Fuel Gauge: All Technical Service Bulletins
Fuel System - SES Lamp ON/Gauge Reads Empty/DTC's Set
Bulletin No.: 05-06-04-008A
Date: April 14, 2005
TECHNICAL
Subject:
Diagnostic Trouble Code (DTC) P1172 or P2636, Fuel Gauge Reads Empty, Service Engine Soon (SES) Light On (Relocate Auxiliary Fuel Tank Vent
Hose)
Models:
2001-2005 Chevrolet Silverado (Cab Chassis Models Only)
2001-2005 GMC Sierra (Cab Chassis Models Only)
with Auxiliary Fuel Tank
Supercede:
This bulletin is being revised to clarify the difference between the auxiliary fuel tank balance hose and vent hose. Please discard Corporate Bulletin
Number 05-06-04-008 (Section 06 - Engine/Propulsion System).
Condition
Some customers may comment that the SES light comes on and the fuel gauge reads empty. when This may occur when the vehicle is parked on an
incline with the engine running.
Diagnosis with a scan tool may reveal a DTC P1172 and/or P2636.
Cause
Important:
A similar condition may occur if the vehicle is fueled with the engine running AND the rear tank is fueled first. The engine must be shut off (as
required by law) during vehicle refueling.
The auxiliary fuel tank vent hose is located in the same "T" connection on the main tank vent hose as the auxiliary tank balance hose. During fuel
transfer, the fuel is pumped out of the auxiliary tank to the main tank via the balance hose. The fuel is then sucked back into the auxiliary tank via the
vent hose rather then dumping the fuel into the main tank. When the Powertrain Control Module (PCM) does not detect a fluid level transfer between
the main tank and the auxiliary tank, the PCM shuts off the auxiliary tank pump and the fuel gauge goes to empty.
Correction
Follow the service procedure below to correct this condition.
1.
Depending on the body upfitter, it may be necessary to raise the vehicle in order to gain access to the auxiliary tank balance hose.
2.
Depending on the body upfitter, it may be necessary to remove the left rear tire/wheel assemblies in order to gain access to the auxiliary tank
balance hose.
