hesitation/stumble/c0035

**1MileCrash** · 07-10-2015, 02:12 PM

Hey guys. I'm looking for some help on this one.

2006 Impala SS with 118k on the clock.

The car has a bad stumble/hesitation on initial take off in 1st gear...worst when the car is "cold" ie...just started up.

The traction light flashes on and off and the engine kills out and there is slight grinding noise which goes away once the traction light goes off. This has been an ongoing issue for the last year or so. I had chalked it up to the transmission, but then today something happened to change my mind.

A few months back I was driving down the road and I noticed a bad rotating grinding. A few days later an ABS code came up which led me to check out the front wheel hubs. They were bad...never mind if the sensors were bad because the bearings were COMPLETELY shot. So I replaced both front wheel bearings with Timkin assemblies with the new ABS sensors. All good.

It still didn't seem to make a difference in the stumbling/hesitation problem however.

Leaving work today I started the car and as all the gauges were sweeping and the lights going out, the traction light and the ABS light stayed on and the DIC gave two messages: "service traction system" and "service brake assist." I had seen these one other time a few weeks back, but the light went off the next time I started the car, so I didn't have a chance to scan the code.

As I was driving, I noticed that with the traction and ABS systems disabled due to the warning lights being on, the hestiation/stumble in 1st was completely gone AND the car shifted quicker and firmer. It acted like a completely different car!

Now keep in mind that I have already replaced both front wheel bearing assemblies...and I could go and redo the left front sicne that is the code that I am getting...C0035...but something nags at me that this won't solve the problem. That I have a loose wire or bad connection somewhere.

Anyone have any insight...I'm at a loss.

**1MileCrash** · 07-10-2015, 05:43 PM

another point worth mentioning.

i went to the hardware store after the car sat for a couple hours. i started it up and turned off the traction control on the dash and the car again did not stumble or hesitate in any way. i'm leaning towards there being a problem in the traction control system or wiring.

**pajeff02** · 07-11-2015, 03:52 AM

Interesting... from what you have posted, I tend to agree. I know on our car when the traction control engages that it kills power in a big way.

**1MileCrash** · 07-11-2015, 01:41 PM

yeah it's almost like it's sensing a wheel slipping on takeoff and it is WAY overcompensating even though there is no wheel slippage. i'm thinking that i'm going to have to take it in to the shop and have it checked out. for now i'll just drive it with the traction control off.

**0rion** · 07-13-2015, 12:18 AM

the easy thing to check would be the wires to the sensors at the wheel. Where are those sensors mounted? I had an issue several years back with ABS and it ended up being rust between the spindle and dust shield. The sensors mounted to that shield and the rust kept them from getting a good ground.