In the last post I made about the Corolla I’d discovered the cause of the TRC and VSC lights illuminating on my dials: A faulty ABS sensor. My local ATS Euromaster had plugged it into their diagnostic machine and it had shown the sensor had a break in the wire. It’s not a big job to replace them but they do come with a big price for such a little item. The garage quoted £150 for a new sensor but after asking around I managed to get a BOSCH replacement posted to me for £75. I was actually told by the garage the sensor would “come out in two pieces” but that’s not the case, so you may be able to get away with a second hand one too.

If you’ve got a faulty front ABS sensor it really is a simple job. I was finished in 30-45 minutes with no dramas at all.

Tools Needed:
– Wheel Wrench
– Jack
– Axle Stands
– 10 & 12mm Sockets & Ratchet
– Pliers
– Wire Brush

How To:
– As always, loosen the wheel nuts before jacking the car up, supporting on an axle stand and removing the wheel.

– Locate the ABS sensor and three bolts you’ll be removing. The ABS sensor will be on the rear of the hub held in by one bolt (10mm). Further up, attached to the shock absorber will be a bracket holding the wire attached with one bolt (12mm). Attached to the inner wheel arch will be the final bracket and the final bolt (10mm).

– Clean up the bolts and round the sensor before trying to remove (with the wire brush). They’ll be a build up of dirt and rust and clean bolts are always easier to work with.

– Remove the 10mm bolt holding the sensor in place first and then work your way up to the remaining two.

– The wire for the sensor then disappears behind the plastic arch liner. It’s held in by some plastic clips that can be a bit fiddly to remove but try to gently remove one or two so that you have enough access to the plug. (It’s not far behind the arch liner) You can hopefully see in that picture the one clip I removed from the arch liner to gain access. One was enough for me.

– The plug itself (sensor side) has a clip that holds it against the chassis. Carefully prise that out with the pliers (or screwdriver). Be gentle with it though, try not to damage the other half or any of the wires.

– Once the plug is detached from the chassis it can be pulled out into the open and the two halves can be separated. The old sensor is out and can be binned (if you want).

– Before you fit the new sensor give all the mounting points a quick clean. The sensor is magnetic so it will pick up any metallic debris that is lying around its hole.

– Fitting is the reverse of removal. Clip together the two halves of the plug and clip that back into place behind the arch liner (and secure that back in place). Fit the two brackets supporting the wire and then fit the sensor back into its hole. I couldn’t find any specific torque values for the bolts but with them being on the smaller side of things I just went with “hand tight” plus a bit more with my ratchet.

If you’re lucky the error code may clear itself and everything will be back to normal. If not, the ECU will need to be reset and the codes cleared. Touch wood, the codes won’t come back.

Disclaimer: I don’t claim to be an all singing, all dancing, fountain of perfect knowledge. My only aim is to try to help you complete this job. If something goes wrong or doesn’t quite happen like it’s supposed to, I take no responsibility. I am not a trained mechanic. I learnt by giving it a go. If you’re not happy with that, take your car to a garage. Make sure you use the right tools for the job and stay safe at all times!

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Unfortunately that’s not quite the end of things for me. Although the random ABS moments seem to have gone the Traction Control and Vehicle Stability Control are still there. That left me in doubt as to whether the sensor was at fault or not so I went back to the garage earlier. Another diagnosis was run and this time no ABS code was thrown, instead, a Steering Angle Sensor issue had popped up. This seems more likely to be the problem after changing the steering rack.

The Steering Angle Sensor reads how much input you’re giving to the steering and can detect a loss of control for the TRC and VSC to assist with. It need’s to be calibrated in a specific way though and if it is out of tolerance it will throw a code and disable the TRC and VSC. It’s not something the garage knew how to fix so I turned to Google. It seems a lot of “stuff” can knock the sensor out of calibration, even a wheel alignment. It looks like a call to a main dealer is in order to recalibrate the sensor but I have found a few possible DIY solutions. I’m going to give them a go tomorrow and write back with my findings. Fingers crossed it works because I don’t really want to pay dealer prices for a fix!