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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
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Experience:  GM Grand Master Technician 2007. 14 years experience.
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2000 Chevy: 3500 hd..flatbed dump conversion ( by me )..front tank

Resolved Question:

2000 Chevy 3500hd flatbed dump conversion (by me). Rear tank does not send fuel to front tank. Do I follow the same procedure as if it was a 98 (This question was previously asked and answered but concerned a 98 3500 hd PU)
Submitted: 5 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 5 years ago.

Welcome, and thanks for using Just Answer. I am Cam, and I will do my best to assist you. When you are finished please click on accept only if you are satisfied. I don't get paid unless you do.Please do not accept if you cannot leave positive feedback. I don't know if you are a tech or a just working on your own vehicle so we may have to fine tune the answer. I only know as much about your problem as you have told me in your post, so my answers will be based on what you tell me so please add all the details you can. About your vehicle, I suggest you test the resistance of the rear fuel tank. If that is out if spec, this will be the result.


Customer: replied 5 years ago.
I have not used the multi meter on the system yet. I have been out straight with business (That is a good thing). I just got this truck and while I am a fair backyard mechanic I have never worked on one of these before,. I do not want to just start replacing parts till I find the defective part. However it is my understanding that there may be a TSB on the 2000 chevey 3500 HD rear fuel tank failing to deliver fuel to the front tank. I understand this was due to a time out issue with the pum0p that would fry the modulator. I just do not know how to test and or tell if my truck has already been serviced per the aformentioned TSB or if I need to replace the transfer pump, sending unit, relay and modulator. As a side note it looks as if the front tank pump/ sending unit is fairly new. It is white plastic whereas the rear is metal and the lines are mildly rusty, tipical for the trucks age and miles (39000).
Expert:  GM Tech (Cam) replied 5 years ago.
#01-06-04-037B: Fuel Transfer Pump Inoperative (Replace Fuel Transfer Module) - (Oct 16, 2001)

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® 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).


Some customers may comment on inoperative secondary fuel tank transfer pumps. In some instances, customers may experience multiple failures of the service replacement pumps.


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.


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



  • Remove the fuel transfer module mounting bolts (1).
  • Remove the fuel transfer module (2).
  • Install the fuel transfer module and the bolts.
  • Connect the fuel transfer module electrical connector.
  • Parts Information





    Module, Fuel Transfer

    C6-7 Conventional Models with Gas Engine

    F6-7 Tilt Cab Models with Diesel Engine


    Module, Fuel Transfer

    1998-2001 C/K 3500 with Gas Engine


    Module, Fuel Transfer

    1996-1997 C/K 3500 with Gas Engine

    1996-2001 C/K 3500 with Diesel Engine


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