K 3500 Truck 4WD V8-5.7L VIN R (1998)
Fuel Pump Balance Module: All Technical Service Bulletins
Fuel Transfer Pump - Is Inoperative
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 01-06-04-037B
Date: October, 2001
TECHNICAL
Subject:
Fuel Transfer Pump inoperative
(Replace Fuel Transfer Module)
Models:
1990-2001 Chevrolet and GMC 6-7H C-Series Conventional Medium Duty Models
With Gas Engine (VINs E, D, B, M, P - RPOs L18, LP4, L21, LRO, LSO)
1997-2001 Chevrolet and GMC 6-7F T-Series Medium Duty Tilt Cab Models
With Isuzu Diesel Engine (VIN 3 - RPO LG4) or Caterpillar(R) Diesel
Engine (VIN C - RPO LG5)
1996-2001 Chevrolet and GMC C/K 3500 (1 Ton) Models
With Gas Engine (VINs G, J, R - RPOs L18, L29, L31) or
Diesel Engine (VIN F - RPO L65)
and Dual Fuel Tanks
This bulletin is being revised to update part usage for C/K 3500 Models in the Parts information. Please discard Corporate Bulletin Number
01-06-04-037A (Section 06 - Engine/Propulsion System).
Condition
Some customers may comment on inoperative secondary fuel tank transfer pumps. In some instances, customers may experience multiple failures of the
service replacement pumps.
Cause
This condition may be caused by the "Four Minute Final Pump Out" feature of the fuel level control module. This feature can command the transfer
pump to on when there is no fuel in the secondary tank.
This command occurs with every ignition cycle for a period of four minutes. These transfer pumps can overheat and become inoperative when they are
run dry.
Customers that never add fuel to the secondary tank can further compound this issue. In these cases, the secondary pump would become inoperative in a
very short period of time.
Correction
Three new transfer pump modules have been released to correct this condition. The new module curtails the "Four Minute Final Pump Out" feature.
When the sender in the secondary tank drops to a resistance reading of 2 ohms, the pump-out feature is disabled. At resistance readings greater than 2
ohms, the pump-out feature will continue to function. However, under this condition there should be enough fuel in the tank to prevent pump failure.
Replace the fuel transfer module using the procedures and part numbers listed below.
C-Series Conventional Cab
