Keppler

I thought I would share the repair information of the common C5 fuel gauge problem I've had for the past 2 years (2002 vert).

Description from the repair order: Fuel gauge goes empty when it has 1/2 tank fuel showing. When filling back up sometimes gauge reads full. Customer has run out of fuel with 3/8 tank showing. Customer has noticed vehicle has 18.5 gallon tank and has run out of fuel showing 14 gallons used when refilled.

Pull TSBS Doc #1411305 fuel system diag. Test fuel pressure. Test for fuel bleed down OK. Check scan data for both sending units. Test by draining fuel from rail and watching for sending unit voltage change. LH sender changes, right does not. Check for proper fuel transfer to jet pump in right tank. Fuel coming from left sender blow out metal transfer line to check for blockage. Check for fuel at inlet for RH fuel sender. Fuel to jet pump but no fuel transfer. Needs sender unit and jet pump. Replace RH sender unit and jet pump. Scan data for senders, vehicle fuel system operates normally after repair.

Parts: 89047748 Module KI 3.107 RH fuel sender assembly $480.00

Labor 3.5 hours
Computer scan $120

Expensive repair but it's great to have a working gas gauge again. I asked if the LH tank could have a similar corrosion problem. They did not disassemble the LH sending unit but said according to all tests it is working normally.

Z06ster

Yep... this fuel gauge thing is really making me . I talked to a service adviser at the local GM dealer. He said $1500 for both sending units removed and replaced, parts and labor. Sounds like your experience was not that costly since it was determined that only one of the sending units needed replacing.

Keppler

You could get by with a lot less cost if you buy all the parts for both tanks online and then find a job shop you trust to do the install.

The part I needed was $480 from the dealer. The online price was $312. My argument to the dealer was why should I pay $480 for a part I could buy for $312. This argument worked for me once but not this time. I reached the point were I just wanted the damn thing fixed.

All the part numbers, labor time, and install instructions are available from AllDataonline. AllData is available from a public library. I printed out 12 pages of detailed instructions to remove and install both sending units.

DeeGee

Great post

I suspect most members just have the sender unit go bad which is why Techron normally fixes it. Apparently sulfur build up is normally the cause. Looks like you had bigger problems.

Thanks for the post.

Vetteman Jack

Thanks for the info. Hopefully no more problems for your car.

bighank

Had sending unit replaced. 2 years later same symptom. Goes to zero whenever it feels like it. I've used Techron and that seems to work. BIGHANK