ABS warning light

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Sun Oct 30, 2016 7:15 am

Completely with Mario - Correct about 4ws/ABS interface and yep, read the codes, that is soo easy and will tell you all!
If you want to bell out the sensors though, the resistances are in the service manual. From memory, they should be a few hundred ohms.

alinton · Post by **alinton** » Thu Jan 12, 2017 3:21 pm

I only just got around to looking at this, because the MOT is due!

It flashes four times, twice.

I'm going-a-looking in the manual now.

A

Confused · Post by **Confused** » Thu Jan 12, 2017 3:48 pm

4 long then 4 short? Then repeats over and over...

If so - that's Rear Right speed sensor.

Which could be the sensor failing, or more likely, the ABS reluctor ring could be damaged.

alinton · Post by **alinton** » Thu Jan 12, 2017 4:35 pm

No looks like 4 short then 4 short.

I think.

Where's the ABS control box?

Confused · Post by **Confused** » Thu Jan 12, 2017 4:40 pm

4 short 4 short is not a valid code.

Record a minute-long video of it showing it repeating, and and post the link here. We'll then tell you what the correct code is.

The ABS unit is behind the driver's side rear seat side trim (if my memory serves me correctly).

Don't go pulling anything apart until you've successfully read the code. You can then reset the ECU, and try it again to see if the same fault is recorded.

alinton · Post by **alinton** » Thu Jan 12, 2017 5:00 pm

Thanks, Here you go...

https://youtu.be/c-Z5UOy2iZE

Confused · Post by **Confused** » Thu Jan 12, 2017 5:20 pm

Ah, OK - it's been a while since I've seen a Prelude's ABS warning lights - didn't remember they don't do the long flashes for 10s!

That's definitely 44. So, that's rear right (driver's side) speed sensor. Before you do anything else, jack that corner up, secure it on axle stands, and put your head under that rear wheel and have a very close look at the ABS ring as you rotate the wheel.

You should see the toothed ring. Look very, very closely, and make sure that there are no cracks in the ring, where two of the teeth are slightly further apart from each other than the rest are.

This is a photo found on Google of a broken ring:

Here's another example:

(These are both from the front of a FWD car, so it might not be quite as obvious to you)

alinton · Post by **alinton** » Thu Jan 12, 2017 5:29 pm

Thanks, not rear right?

Confused · Post by **Confused** » Thu Jan 12, 2017 5:30 pm

Yes, sorry, you are correct

alinton · Post by **alinton** » Thu Jan 12, 2017 5:56 pm

OK thanks I'll grovel around underneath tomorrow. I see from the manual you can check the resistances of the sensors from the control box wiring. Might try that too.

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