C6 Corvette - No Traction Control & ABS Light On

JOHNKUEHNE

MEMBER
2011 CHEVROLET CORVETTE
6.2L
V8
2WD
AUTOMATIC
101,000 MILES

Would get loss of traction control periodically and engine restart would reset and allow traction control to work. Problem got worse and then ABS trouble light and check engine light would both come on. OBD2 codes: C0450, C0561, C0040. Replaced all (4) wheel hub assemblies with built in wheel speed sensor - issue improved slightly. Traction control worked again somewhat, but began to require engine restart to reset and now both check engine and ABS light on all the time and no traction control (message on dash always notes get vehicle serviced at start up). I get code for ABS controller. I expect it needs to be replaced, but Question#1: Is there a way to validate with testing (Have OBD2 and HP Tuners, but neither seems to have a way to check each wheel speed sensor or ABS controller - should I get a bi-directional scanner, if so which one?). Question#2: Since I still see code for ABS controller and replaced all wheel speed sensors and have "vehicle serviced" message when car starts up should I replace the ABS Controller? New is $800 - for AC Delco GM Original Equipment 25994201 Electronic Brake Control Module, used/untested 76K is $300, or should I try to get mine rebuilt?

1 Reply

STEVE W.

MECHANIC
13,571 POSTS

OK the codes you have point at a fault in the circuitry for the ABS system. The C0561 is basically saying the there is a fault and the ABS is disabled and codes are stored. The C0040-00 and C0040-05 codes both say there is a fault in the circuitry in the right from wheel speed sensor. The C0450 code is related to the power steering assist controller. It get's data from the ABS module so that code may be a side effect of the ABS being disabled. The circuit code points more to a bad connection in the harness than a bad sensor. Does your OBD tool allow you to look at live data from the wheel speed sensors? If yes then you could watch that and see if there is no data or if the data drops out while turning or if you flex the harness. GM had issues with the right side harness on many vehicles around that time period so it's possible you are a victim of that. If your scan tool doesn't show you live data then you might want to upgrade to something better like one of the Autel Maxisys or Launch tools like the CRP 910 or Millennium models. Topdon Artidiag tools are also real good. All of them have various levels of abilities and control and cover multiple makes and models.
Now if you see that the right front signal is gone you will need to test the circuit Fortunately GM made this a bit easier as those are active sensors. There is a reference voltage feed to the sensor and the sensor acts like a switch turning the signal on and off as the magnetic ring passes the hall effect in the sensor. If you unplug the sensor one wire should have 12 volts on it with the key on. If you have that then suspect the other wire is broken going to the ABS module. Repair that and then erase the codes. Take it for a drive and see if any of the codes return.

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