My regal gs just shut down and wouldnt come out of park, even when the engine started back up. After a few minutes it would start and things were fine. My mechanic replaced the switch and now it doesn't die but the oil light is the seat belt light, the trac loc is the check engine light, the temp guage is reading backwards,well you get the picture. also the odometer is crazy and the MODE light is out. The mechanic says a $200 body control module and a reprogramming will fix it. What do you think?

I don't know about that. Sounds like some wiring got messed up for the instrument panel (IP). Missing a ground or something. I don't think the BCM has anything to do with trac light, the oil light or the temperature gauge problem. If the SES light is on get it scanned and see what DTC error codes show.

Which switch was replaced?

The ignition switch was replaced.

The ignition switch was replaced.

Did the symptoms appear after the ignition switch was replaced or there before? The ignition switch is not just electrical contacts at the key switch module but a complete wiring harness. Maybe the connector in the steering column is not tight. Sounds like 12v or a ground is not getting to the IP.

the initial problem was that the engine would die but you could start it up and drive it for a while before it would die again. Then it would die and the speedometer would act up and go wildly back and forth. Then it got so it woul not come out of park and the brake pedal was real hard. After about twenty minutes it would be normal but later it would act up again. I checked all the ground connections, even the one under the carpet by the door sill and cleaned the starter connections etc. Frustrated I took it to a mechanic and he said he disconnected the ignition switch harness and by hot wiring the switch he could make it run and come out of park etc. He replaced the ignition switch and it did fix it so it doesn't die and it comes out of park ok but now the odometer is reading crazy, the mode light is out, the oil light goes out when I connect the seat belt, the traction button turns on the ses light on the left and goes off when I turn the traction off, the low fuel light stays on, the temp guage reads hot but as the engine warms reads backwards down th about 3/4 of the guage and the temp controller reads in centigrade and wont let me switch back and the cruise control doesn't work!! How's that for a teaser? It has me baffled. Thanks in advance

the initial problem was that the engine would die but you could start it up and drive it for a while before it would die again. Then it would die and the speedometer would act up and go wildly back and forth. Then it got so it woul not come out of park and the brake pedal was real hard. After about twenty minutes it would be normal but later it would act up again. I checked all the ground connections, even the one under the carpet by the door sill and cleaned the starter connections etc. Frustrated I took it to a mechanic and he said he disconnected the ignition switch harness and by hot wiring the switch he could make it run and come out of park etc. He replaced the ignition switch and it did fix it so it doesn't die and it comes out of park ok but now the odometer is reading crazy, the mode light is out, the oil light goes out when I connect the seat belt, the traction button turns on the ses light on the left and goes off when I turn the traction off, the low fuel light stays on, the temp guage reads hot but as the engine warms reads backwards down th about 3/4 of the guage and the temp controller reads in centigrade and wont let me switch back and the cruise control doesn't work!! How's that for a teaser? It has me baffled. Thanks in advance

Thanks for the additional info. Nothing worse than electrical problems. It's possible that the ignition switch was the root of the problem. I've dismantled the module containing the electrical contact part of the ignition switch and harness and have seen contacts burnt or arced out. The arcing that results may have damaged the IP. From all of your symptoms I would rule out the BCM. I reviewed my GM Regal service manual to confirm.

It sounds more like the instrument panel cluster. There is a electronic component within the IP called a Panel Logic Decoder Module. It controls the routing of all sensor and switch inputs to the respective gauges and idiot lights. There are a series of diodes that work as logic gates and for isolation purposes.

The only other suggestion I would have is to remove the dash bezel and IP cluster. Remove the two electrical connectors and then reseat. I'd bank on the IP cluster. Hope the info helps. Good luck!

I appreciate your help. I am going to dig into it this week. Again thanks

I appreciate your help. I am going to dig into it this week. Again thanks

You're welcome and let us know how it turns out. Good luck!