Traction control causing erratic AF ratios?
Thread Starter
Instructor
Joined: Jun 2008
Posts: 209
Likes: 1
From: NY
Traction control causing erratic AF ratios?
Long shot, but does anyone know if having the traction control on would cause erratic AF ratios? I'm troubleshooting erratic and inconsistant AF ratios on my car and it's down to either the actual sensor control box (FJO) or the traction control. The car was on the dyno recently and the AF ratios were consistant on the dyno, but we did have the traction control off on the dyno.
Thanks
Travis
Thanks
Travis
Thread Starter
Instructor
Joined: Jun 2008
Posts: 209
Likes: 1
From: NY
I always drive with TC off. I did however forget 2 times this last week to turn it off and when hitting 2nd gear and spinning a little the car nosed over horribly when the TC activated. It did it at the top of 2nd also when tires spun. I hated TC when I was NA and hate it even more with the s/c as it really upsets the engine bad.
Burning Brakes
Joined: Feb 2006
Posts: 844
Likes: 46
From: Southaven MS
I don't know how it effects A/F but I can tell you that it does. I was logging my car while pushing it hard in comp mode, and it was somehow making the A/F ratio very lean on the log chart. I had a friend tell me it was the traction control system, and I didn't believe it, but when I logged it again with traction control off the A/F ratio was right on with what it had been on the dyno a few days before.
Burning Brakes
Joined: Feb 2006
Posts: 844
Likes: 46
From: Southaven MS
Tech Contributor
Joined: Oct 1999
Posts: 41,032
Likes: 9,790
From: Charlotte, NC (formerly Endicott, NY)
When tire spin goes beyond a certain dead band range in the EBCM it requests a torque reduction from the PCM. From the Service Manual:
When drive wheel slip is noted while the brake is not applied, the EBCM will enter traction control mode.
First, the EBCM requests the PCM to reduce the amount of torque to the drive wheels via the requested torque signal circuit. The PCM reduces torque to the drive wheels by retarding spark timing and turning off fuel injectors. The PCM reports the amount torque delivered to the drive wheels via the delivered torque signal circuit.
Bill
When drive wheel slip is noted while the brake is not applied, the EBCM will enter traction control mode.
First, the EBCM requests the PCM to reduce the amount of torque to the drive wheels via the requested torque signal circuit. The PCM reduces torque to the drive wheels by retarding spark timing and turning off fuel injectors. The PCM reports the amount torque delivered to the drive wheels via the delivered torque signal circuit.
Bill
