I have one of my speed sensors not working so the traction control is disabled , How do you test to find the one not working, on a 2009 Chevy HHR LS 2.2 , Also i had a check engine light on and the temp gauge stopped working and the digital read out was blank . after doing some test i found the coolant reserve to be a quart low after topping off the reserve to the indicated level and clearing the code the gauge and digital read out both worked properly again and the check engine light remained off . so i just need to know how to test the wheel speed sensors to find the one not working , can some one help on that ? Thank You .. Blue's .

 

I don't know how to test the wheel sensors, but they are integral to the hubs. So, chances are you have a bad hub. Check all 4 for ANY end play. If you can feel it, it's too much. Maybe a well equipped shop with an ABS scanner could tell, but it takes a really good ($$) scanner.

Keep an eye on your coolant it's going somewhere. If it was a quart low chances are it was even lower, check the level under the pressure cap when cold it should fill the hose. The pressure cap itself may be the problem, very small leaks just let steam out that leaves no evidence behind.

 

Here's a link to a comprehensive article on testing ABS wheel speed sensors, it's not a DIY prospect unless you have the proper training and knowledge.

http://www.underhoodservice.com/Arti...nd_scopes.aspx

As you can see from the article, testing of speed sensors should be left to your technician or dealership. Even though HHR's use the simpler two wire "Passive" sensors, testing them yourself is not a smart idea, even if you're trying to save some bucks.

P.S. to the forum!