We got our 2004 Crossfire in April 2018. I have been driving it to work 40 miles round trip almost daily since. About six months ago, the tire pressure light and bulb out light started coming on (for a couple of hours or days) and going off randomly. The BAS/ESP light came on and went off a couple of times as well. I checked for burned out bulbs and low tire pressure and when they were fine, we ignored the lights. About two months ago, both air bag warning lights came on and stayed on. A month ago, while turning a corner from a complete stop, the traction control light came on and the computer (?) applied the brakes twice, the BAS/ESP light came on and the traction control light went off. My husband had me shut off the traction control till we could figure out what was wrong. The car drove fine the next day. The following day I drove to work, traction control off. After about 20 minutes driving, the traction control light started flashing. When I applied the brakes, they locked up and the car fishtailed. I got it to the side of the road, the traction control light stopped flashing and the BAS/ESP light came on.

We took it to a mechanic and he ran the codes. There were a lot (around 35) but nothing matched what was going on with the car. A friend suggested it was a bad ground, my nephew thought it was the ABS control module/pump. My husband checked the grounds he could find and has test driven it. Two or three times the computer has applied the brakes but it doesn’t happen every time.

If anybody has any ideas or suggestions, we would appreciate it. Now the car is parked since we can’t drive it or sell it.

 

I can't imagine how the computer can apply the brakes, there's no mechanism for it in the system. The anti-lock brakes work by relieving pressure from any wheel that is sliding. Probably what you felt as the computer applying the brakes was the car down shifting (I presume this is an automatic which may be the source of the problem).
As a place to start I would first of all disconnect the battery and short the battery cables together with the lights on. This should reset the computer and hopefully clear the codes. Then I would remove fuses #17 and 18 to disable the traction control. Then take if for a test drive.

 

How old is the alternator ? I just went through some similar things. When these cars computers get low voltage they do strange things. I replaced the alternator. After the
right rear abs sensor had died. Found out that with the roadster when you have a abs sensor out...you can't put the top down. Replaced sensor now all is good....for now. Now if it would just stop raining.

 

When the cruise control is engaged, I have found on an automatic when going down a hill, not only can the car downshift, but it can also apply braking. Don't know if its related to your issue. Good luck with that one.

 

That is incorrect. The Acceleration Slip Regulation (ASR) applies the brakes at speeds up to 50 mph. ASR gets input from all wheel speed sensors, the parking brake switch, stop light switch, the PCM, TCM and the ESP control switch. The information is feed to the ABS circuits in the Controller Anti-Lock Brake (CAB). They all are related.
Clearing all the codes is a good place to start, drive the car and then read codes again. As has been suggested steady reliable electric supply is necessary for the system to operate properly.

By any chance does your wing go up randomly ? Does it stay up even when stopped?

 

We changed the oil and filters when we got it and put new tires on 2 months ago but haven't had to replace anything else so I don't know how old the alternator or battery is. Really didn't have any problems until the warning lights started coming on/going off a few months ago and then the braking issue. Would the air bag warning lights be part of the same problem or a separate issue? The wing works fine.

 

I asked about the wing as it is an indicator of a bad battery when it deploys and won't go back down.
With all the problems indicated by the various indicator lights and the braking problem the air bag light may just be part of the encompassing problem. Perhaps corrosion at a ground on the instrument cluster circuit. Normally I would say no connection between air bag light and other problems, because all the air bags use the Occupant Restraint Controller as their common "brain" and the air bag indicator light is basically controlled by the ORC.
Which gets us back to clearing all the codes, take a short trip and read the codes again. See what comes up. Try disconnecting the battery over night, before you start out on the short test drive. That should clear most codes. Then get the codes read again. GET the exact code numbers, not just some explanation of what was found. A lot can be misunderstood without the exact coded number.

 

Do the crossfires have ASR ?

 

yes