My Impala- 2009, 3.5L V6- will have occasional, erratic ABS and Traction Control lights that are incredibly random, coming on and off in an instant, over a couple of days, or staying off for weeks. Those codes are C0035-00 and C0035-OF, left front wheel speed sensor circuit and left front wheel speed sensor signal erratic respectively.

At first, the issue will present as an overactive ABS, usually right after pulling out of a parking spot in the morning. The left front wheel will act as if it is losing traction, the traction control will kick on, light will flash. This presents even during dry conditions, so traction should not be an issue. Then, the ABS and Traction Control lights will begin to come on, but then turn right back off, before finally coming on and staying on over a long period of time.

As far as attempts at repairs go, I have replaced the front hub assembly- internal wheel speed sensor- twice, once as an attempt to fix the ABS issue and again because the wires coming from the hub to the car ABS harness broke. However, this has still not fixed the problem.

Any advice, previous similar experiences would be helpful.

The front left and right wiring harness is known to have internal wiring breaks, often due to the crimping of the wire to something with a small clamp from the factory - which causes the wiring inside the insulation to fracture, although the external wiring insulation is intact (and the wiring looks “good” to a visual inspection).

When turning the steering wheel, it stresses the wiring and causes intermittent and brief DIC warning messages, and may trigger the ABS system briefly - especially if there is an internal wiring break.

GM offers pigtails to replace the front left and right wiring harness, to avoid complete harness replacement. They pigtails are specific to the left and right sides, and specific to certain model year cars. You should look for any clamps around the wire - and see if the clamps are swollen from oxidation (which stresses the wiring). Using your eyes and fingers, closely examine the wiring to see if you feel a suspect area. GM did not allow enough slack in the wiring (and clamped many of them) - so they are intermittent failure items.

Another cause I have seen on a 2012 Impala was worn REAR brake pads, which caused a drop in brake fluid in the master cylinder. When accelerating, stopping or turning, the low fluid triggered a low fluid alert - which also set off the ABS / Traction Control / Stability control warning - but didn’t set a code.

I previously owned 2008, 2011 and 2012 Impala LTZ models - purchased new, and now own a 2014 Impala 2TLZ - also purchased new.

 

part numbers on the front L & R pigtails?

 

You can't just buy a wire harness for an impala not my 07 anyways the wheel speed sensor is connected straight to the hub it's all one part so you have to replace the entire hub cause you can not just replace the wheel speed sensor by itself