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Toolhut
Toolhut, ASE Certified Technician
Category: GMC
Satisfied Customers: 550
Experience:  Owner of a mobile diagnostics company assisting auto technicians with difficult vehicles
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I am having problems with the fuel injectors.

Customer Question

I am having problems with the fuel injectors.
Submitted: 1 year ago.
Category: GMC
Expert:  Toolhut replied 1 year ago.

Hi, My Name is***** have over 20 years experience repairing vehicles. I am a ASE Certified Master Auto Technician. I am confident we can resolve your problem together.Please remember I don't know your skill level. I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies to get to a satisfactory resolution.I also try to give all of the information you may need expecting a positive rating. If there is any reason I cannot get a positive rating please let me know.

What kind of trouble are you having?

Customer: replied 1 year ago.
I bought this truck with this problem already so I am not sure what was done previously other than the fuel injector driver module was replaced. The truck is currently running with 3 injectors and there is no pulses on the other injectors. I called a technician that had a snap on computer and he came by and did a complete reset and the truck ran great with all 8 injectors working perfectly. The next day I went to crank up the truck and we were back to square one (3 injectors working and no pulse to the rest of the injectors). Unfortunately after the truck is off for a period of time it loses its synchronization. What should I do?
Expert:  Toolhut replied 1 year ago.

Hi, My Name is***** have over 20 years experience repairing vehicles. I am a ASE Certified Master Auto Technician. I am confident we can resolve your problem together.Please remember I don't know your skill level. I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies to get to a satisfactory resolution.I also try to give all of the information you may need expecting a positive rating. If there is any reason I cannot get a positive rating please let me know.

My suspicion is that either your FICM module has failed or you have a shorted fuel injector causing trouble in the FICM. I would check the resistance of the injectors at the FICM using the schematic I have attached. If the injector resistance checks out I would replace the FICM and if it doesnt I would replace the injectors

Customer: replied 1 year ago.
I did not receive the attachment to check the resistance on the injectors. Also if I replace the FICM does it need to be programmed or synchronized?
Expert:  Toolhut replied 1 year ago.

Yes it will need to be programmed

Expert:  Toolhut replied 1 year ago.

FICM diagram

Customer: replied 1 year ago.
Is a reset with the snap on scanner sufficient? or Is there an other process to program the FICM?
Expert:  Toolhut replied 1 year ago.

You have to program the FICM. Some of the remans come programmed and for that the snap on reset is sufficient

Expert:  Toolhut replied 1 year ago.

It has been a couple of days since I have heard from you. Do you still need assistance? I have also noticed that I have not received a rating from you. If for some reason you question did not get answered please reply. I am only compensated for my time when you leave a positive rating. Your understanding is appreciated.

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