Help with 2010 Mazda CX-7 AWD Touring ABS/TCS lights

Maintenance/Repairs
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1

OK so…about 2 weeks ago I replaced the battery in my 2010 Mazda CX-7 AWD Touring. After the battery swap, the traction control (tcs) and ABS lights in the dash lit up. I turned the steering wheel all the way right, then all way left, then back to center, turned the car off then restarted it and the lights were gone and everything was great.

A little less than a week later, I was on my way home from work about 35 miles in a 40 mile commute, when out of the clear blue the TCS and ABS lights came on. I drove home since I was close and there was no danger.

When I got home I tried to reset the steering wheel/angle sensor by doing what I did the first time, cranking the wheel all the right then all the way left, back to center then restarting the car. It did not work.

I tried again cranking the wheel all the way left, then right, then back to center then restarting the car. It did not work.

I completely disconnected the battery, let it sit for a while, held my foot on the brake pedal for a minute or so to drain any residual memory then re-installed the battery. As expected, the TCS and ABS lights came on. I tried the reset using the methods above, at least 3 or 4 different times. It did not work.

I checked all the fuses, brake lights, etc. and can find nothing wrong but the stupid lights will not go off. Any ideas? THANK YOU!

2

Well maybe, just maybe, there is actually something wrong with your ABS or traction control. Likely a wheelspeed sensor.

You can get those error codes read to find out the actual cause but the free reads from the auto parts stores can’t read ABS/TCS codes. You need a more professional reader for that. Take it into a shop if you don’t want to buy one for yourself.

1 Like
3

There may be a problem with the ABS.

If the ABS light turns on for a fault, the TCS light will automatically turn on because it utilizes the ABS system to function.

So, what needs to be done is have a scanner connected to the vehicle to see if there are any ABS codes.

Tester

4

So I put my i400 reader on the car and it reported a communication failure at the left front ABS wheel sensor; the connector is under the battery tray so maybe I knocked something loose when I replaced the battery (I removed the tray to clean it all due to my OCD) but the lights didn’t light up for quite a few days after that. I will check the sensor leads and clean it up when I get a chance and see what happens.

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5

A damaged wire or dirty pickup can both cause sensor problems. If you can’t see any of that, it might make sense to must replace it.