Hi All
My Mk2 1.8iS registered September 1999, had a problem with the ABS light coming on. The usual intermittent becoming worse over time. Unfortunately the diagnostic unit under the bonnet has no terminals to test the ABS (these are present on later production cars). The only way to identify which sensor is giving the problem is to unplug the each connector and measure the resistance using a multi-meter. This identified the front passenger ABS sensor as being the problem (open circuit).
After reading the reviews on the Chinese units I decided to bite the bullet and get a genuine Mazda one at some considerable cost. I plugged this in before starting work to ensure it solved the problem, which it did.
I was going to get my local friendly garage to fit it for me, again having read reviews about sheared bolts/seized sensor but they have closed due to Coronovirus.
As a self isolating sprightly 72 year with only 3 underlying health issues I decided to have a go myself.
I used loads of release agent, applied over 3 days, then tackled the bolt. Despite taking great care the bolt head sheared. I then tried the sensor itself trying to lever/twist it out but the head part came away.
I then tried the bolt stub using locking pliers at first, then heat plus locking pliers - no go.
Next I got out my trusty Dremel, cut off the stub and and started drilling using my extensive collection of old/blunt drill bits. Success eventually came but I needed to tap a new thread.
Then by a combination of drilling, chiselling and brute force I was able to get the remains of the old sensor out and clean everything up.
Fitting the new unit was fine. I greased the outside of the sensor to ensure it slipped in nicely. Job done!
Recommendations
Even if you have diagnostics it’probably worth while doubling checking with a multi-meter. A good sensor will probably give a reading around the 1500/1600 ohm mark.A bad one an open circuit.
Before you start work ensure you have:
Sharp drill bits of the appropriate size.
An M8 tap.
Replacement bolt(s).
All the best in these difficult times.
John