ABS light stuck on

  1. My model of MX-5 is: __NC 3.5
  2. I’m based near: __Kidderminster
  3. I’m looking for technical help or recommendations on: __ABS light

Hadn’t driven car for a few weeks until today. ABS light came on immediately as I left home and stayed on. No other errors. Put my cheap and cheerful OBD reader on when I came home and it found no errors. Fluid reservoir is full.

Am toying with disconnecting the battery to see if it clears. Any suggestions folks?

Have you had a look under the car to see if and of the abs sensor cables are rodent chewed ?

Yes - I would expect them to show on the obd reader but its a free & easy check

Another thought - did the battery go flat ?

If yes - after starting the car - you need to turn the steering lock to lock to calibrate the angle sensor.
Then drive the car 100 mtrs - switch off the engine - then re start the car.
That should put all the lights out

Haven’t looked at cables but will do, although rodent damage very unlikely. Battery is/was good so not that.

I’ve read online that some OBD readers don’t read ABS faults and mine is a cheap Ebay one. Tried two different apps on phone to talk to it and both can’t find any fault.

For my NC I use ForScan loaded on a laptop with a usb cable OBD connector.

It has the capability to program replacement keys so it should be able to do ABS functions.

You can install it with the FREE 30 day licence - do your diagnosis - then uninstall it if needed.

This is the OBD cable

Thanks for the info. Spoke to friend who’s retired mechanic who says almost certainly one of the wheel sensors knackered but he sold his OBD scanner so I’m going to book it in to my local trusted garage and let them sort it.

had this with my audi unplugged the abs unit and that cleared it, battery didnt

That is a classic “bad connection” symptom.

Servisol Super 10 is your economical friend in those instances.

Update. We went out today for a decent run and after about 30 miles the light went off and has stayed off. Very odd and am just hoping it stays off.

Wonder if one of the wires or connectors has allowed water in and a decent run in the dry has cleared it.

Very unlikely as it lives under cover. Have tweaked my back at the moment but when it’s better will take wheels off and have a good look at the sensors.

An update. Light came on again. My local garage put their OBD reader on it and diagnosed rear left sensor no output. Only place they could find to get a new sensor was local Mazda dealer at £112.80! MX5 parts sell genuine Mazda for £51 but no stock. I found BOFI racing online had pattern ones for £12 so decided to buy one. Luckily I did as Mazda still not supplied one 2 weeks later and MOT due soon. Pattern one fitted today and light now out.

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Well, you could afford to replace the BOFI sensor at least 9 times and still be in pocket compared to if the Mazda dealer supplied item :+1:

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