2000 Buick Regal 'service engine soon' light won't stay off

I’m trying to get my 2000 Regal to pass inspection, but every time I have it serviced and need to drive it for approx. 100 miles before the emmissions test, the service engine soon light comes back on. Can a bad gas module in the gas tank be the culprit? My gas gauge has not worked for several years and it didn’t cause the service light to come on before, but the mechanic said that is the only ‘code’ that comes up on diagnostics.

What’s the actual “code” he’s talking about? Post that back here.

A “Gas Module”?? That’s a new one…Please post the exact code here to get a better answer…

I think he said 463 or 483…?

"DTC P0463
Circuit Description

The fuel level sensor changes resistance based on fuel level. The PCM monitors the signal circuit of the fuel level sensor in order to determine fuel level. When the fuel tank is full, the sensor resistance is high and the PCM senses a high signal voltage. When the fuel tank is empty, the sensor resistance is low and the PCM senses a low signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the total remaining fuel percent in the tank. The PCM sends the fuel level percent via the class 2 serial data circuit to the IPC in order to control the fuel gage. The fuel level information is also used for misfire and EVAP diagnostics."

Since it’s part of the EVAP system, it’s emissions related, giving the State the power to force you to make repairs…

Great… this is gonna cost me!

I almost never say this, but you might want to ask a GM dealer to look at this. The cryptic note about the sender operation being tied to misfire/evap diagnostics IMHO indicates a need to have someone with very specific, professionalized knowledge of this GM system. If your mechanic has a factory service manual for the vehicle then s/he should be able to figure it out. But all indications at the moment are to the contrary.

The problem is that with things like internal fuel tank and evap system issues misdiagnosis rapidly gets very expensive. You want the right diagnosis the first time - no guessing.

I agree with Roller…You should not pay for guesswork…When you agree to a repair estimate, do so ONLY if they will guarantee it will fix the problem…

Running a finance company for parts changers is NOT something you want to do…

If you are so inclined, perhaps you can locate a used part in a salvage yard (it’s inside the fuel tank), pull it, and install it yourself…MUCH cheaper, but a lot of work…

Thanx to all for the great advice!