C1241, c1249(ABS) and P0724(check engine)

Recently saw in increase in rpms when in first gear acceleration. Seems almost like it was delayed and then would be fine after first gear. When idling? Rpms drop to 600-700. After a week, the ABS light came on and threw two codes(c1241 and c1249). Low voltage to abs and brake switch. Few hours later the same day, the check engine came on and threw p0724(brake switch “b” circuit high). Only once I noticed that when I pressed the brake, the interior lights would dim, but not the headlights. Had my battery and alternator tested before the check engine came on but with the abs light on and both were good but bad starting system. Was researching and it seems like my brake switch could be an issue? Replaced alternator about 5 months ago. Let me know what you guys think, thank you.

 

First off are your brake lights staying on at times or come on if you just barely touch the brake pedal? If yes then you need to check into the brake switch and make sure it's adjusted properly and that the pad that presses it in is in place.
If no then have you done any modifications to the rear lights or center stop light recently?

 

Hi! Thank you for the response. My brake lights work as supposed to and haven’t seen an issue and tested them earlier today. I have not done any modifications regarding the tail lights or center stop light. I was thinking I have an issue with my brake switch and just came to see if anyone had an opinion. Thanks

 

If the switch was stuck/sticking on your brake lights would be on at the same time.

The C1249 means the Skid Control ECU is seeing an open in the stop light circuit

The P0724 means the ECM is seeing a constant brake signal over 5 or more stop and acceleration events.

Both of these can be caused by stray voltage on the stop light circuit, I think I'd start with checking voltage between Pin 1 (Blue) at the stop light switch and a known good ground. Should be 0v.

 

Thank you for the input.

 

Ok well back again. I was curious and reset the check engine code. It removed the light along with the c1241 code. I scanned the codes again after driving it for a bit and there was no longer a check engine code nor abs light on dash. I turned the headlights on bc I knew the abs had to be a voltage problem and sure enough the abs light came on, the c1249 code and the c1241 was gone along with the po724 code too.
Drove it around the block and the check engine light didn’t come on. However, of course I am still having the delay in throttle response. It seems like it isn’t recognizing that my foot is off the brake and now on the throttle. I checked the brake switch to make sure the brake pedal was releasing from that top switch part, and it was. Taillights work too. Also, when brake is pressed, dash and radio lights dim.

Honestly what I’m really worried about is the delayed throttle response and if that is tied into the voltage or brake switch problem or possibly the torque converter which I hope not. Just need some opinions as the shops earliest appointment is two weeks from now and need my car, thanks!

 

You need to do some voltage checks like I said ablove, I would also voltage drop check between the negative battery terminal and the main grounds (Body, Frame, and Engine) with some loads turned on.

The delayed response is more than likely the brake override kicking in since the ECM is seeing a brake switch input when it shouldn't.

 

Alright well to help anyone else out that may be having a similar issue, it was my brake light. It wasn’t noticeable bad to the naked eye and had to be inspected electrically. Ultimately the light was shorting out and causing these issues.