My car had a head cam package installed. About a week later my dic will randomly show the message service traction system. My car is an auto. I DO NOT get a normal check engine light or reduced engine power and the car runs and shifts fine. The message comes on randomly in all different gears and at all different speeds, stays on for about a minute and goes away. While the message is up my little traction off light comes on and the traction button by the shifter does nothing. The only effect is i can not go WOT the car will just hit the rev limiter and wont shift. What could this be? any help would be greatly appriciated.

 

anyone? if i go to autozone will it give me a code since a traditional engine light is not comming on. and the message only stays on for a minute or two tops.

 

who did the install? what do they have to say about it?

 

they cleaned the vehicle speed sensors and said they were really dirty for free. They went back through the tune and could not find any problems. They recomended changing out either the wheel bearing or hub assembly i cant remember which, but either of those is a little pricey. I was kind of hoping it was maybe a sensor going bad or something like that. They could not pull a traditional check engine code as it does not light up or throw one.

 

Good luck. My 2008 has been in the shop for 5 weeks this year and still no answers.

 

First, it is impossible to clean the sensors as they are sealed inside the hub. They may have cleaned the connectors but this doesn't sound like your problem. If the speed sensors are giving erratic but permissible wheel speed frequency changes TC can be actuated.

Check engine codes can drive a service traction message but in that case the EBCM code just tells you to see what engine codes are set.

Since you don't have a check engine light with the Service message that indicates there is an issue with the ABS (TC is a function of the ABS). The ABS system retains some history codes but most codes are reset upon engine start so you need to wait until you get a Service Message and then travel to a store or shop that has an OBDII scanner that can read ABS codes. That will point you to the problem area. Since the message comes and goes I wouldn't shut off the car before plugging the scanner into the diagnostic port. Tech 2 can read all sorts of info that basic scanners can't read so I don't know if the scanner will give you the extension codes that follow the main code or show any history codes.

A hub that is loose could cause a variation in wheel speed frequency that could be interpreted by the EBCM that it needs to activate TC. Problem is you need to know which hub. Sometimes you can tell by putting the car in the air with the wheels not resting on anything, placing your hands on each wheel in the 12 and 6 positions and see if you can rock it up and down in the vertical direction. If you get excessive movement that hub is a candidate for replacement. Front hubs are easy to do and Timken hubs can be purchased from Auto Zone for around $150. Rear hubs are more involved due to the axle shaft that goes through them. If you have the codes they may direct you to a hub causing the problem if it is being caused by a hub.

The reason the TC button doesn't do anything when you see that message is TC is shut off by the EBCM so the button can't do anything until the system is reset by restarting the engine. Whenever you see a Service ABS or TC or AH Message that means the applicable system has been shut down so it will not interfere with the car's base brake or engine control systems.

Bill

 

thanks bill ill show this message to my tuner and shop the next time im up there.