[HotRodx10]

Occasional "Service Brake Assist" & "Service Traction Control"

My '06 Chevy Impala pops up those 2 warnings on the DIC every few months. I ignore it, and it goes away after a few days. Anyone know what causes it, or what I need to clean or repair to stop it from happening?

 

[Windows on Wash]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Check the wheel speed sensors and reluctor rings for debris.

 

[HotRodx10]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Thanks, Windows. Debris in the wheel speed sensors sound logical. The reluctor ring/wheel is on the crankshaft, though, isn't it?

 

[Windows on Wash]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Wheel speed ring.


https://repairpal.com/obd-ii-code-c0040

 

[HotRodx10]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Wheel speed ring.

Oh, that one! Now it makes sense. Thanks.

 

[lenaitch]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Could also be a wheel bearing. The clearances for the sensor are pretty tight and if a bearing is starting to wear that clearance may get out of spec.

 

[polarzak]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Could also be a wheel bearing. The clearances for the sensor are pretty tight and if a bearing is starting to wear that clearance may get out of spec.

I had a wheel bearing go on my 06, and never had any messages in the DIC. Just a lovely grinding growl from the bearing. Just an FYI.
As already suggested, check for debris and check the electric connectors.

 

[lenaitch]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

I had a wheel bearing go on my 06, and never had any messages in the DIC. Just a lovely grinding growl from the bearing. Just an FYI.
As already suggested, check for debris and check the electric connectors.

It happened to me on a Nissan. Intermittent ABS/traction faults. Turns out the bearing was getting sloppy, just enough to let the sensor clearance/alignment to get out of whack. No bearing noise. Sensors and wiring good bets too.

 

[SPS-1]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

I once had an ABS system warning come in. Took it into the shop and they found a brake light bulb was burnt out. I was surprised I didn't get some other indication such as quick turn signal indicator, but very relieved by the cost of changing a bulb compared to the potential cost of some of the alternatives.

 

[HotRodx10]

Re: Occasional "Service Brake Assist" & "Service Traction Control"

Great advice everyone! Thank you!


I'll start with cleaning up around the wheel speed sensors and checking for sloppy wheel bearing when I do the brakes, which I plan to do in the next month or so. I'll update when I do.