I did the blink test on my 89 and got 32. Right front sensor. Swapped it for a good one and just taken car for a quick drive to clear the code. No luck. Re did the blink test and got the same code. Any suggestions gratefully appreciated. This car will make you suicidal!!

 

brinny,

The implication of what you've concluded is that you seem to have a problem with either the sensor plug connection, the wiring back to the abs ecu, or the ecu itself.

The order in which I would check it is:

- the integrity of the sensor plug
- swapping the pinout of the faulty and one good sensor at the ecu to see if the problem swaps or remains the same (then its the ecu)
- the integrity of the sensors wiring back to the ecu

Good luck

Paul

 

thanks paul. Can you explain a bit more on how to swap the pin out of good sensor please

 

brinny,

I'll need to check through my wiring diagrams and have a look at my own car. But essentially the sensors terminate back at the input plug to the abs ecu. If you can verify through the wiring diagram, which wires are taking the input feeds of the sensors into the ecu, then you could temporarily swap around the pins at the ecu plug, of the fault reporting sensor and one of the other sensors. If the blink fault code then reports onto the swapped sensor circuit, you know that your problem lies in the wiring somewhere from the ecu to that original faulty sensor. But if the blink code returns the original 32 code, it implies that the fault lies in the ecu circuitry.

Hope that makes sense. If you give me a day or two, I'll get down to my own car and look up the wiring diagrams, in case you haven't got them.

Cheers

Paul

 

PS I really wouldn't expect it to be an abs ecu problem. It's far more likely to lie in the wiring or sensor plug of that Right front sensor imo.

 

Ok Paul thanks. I had a quick look and the plug seems ok? I did a continuity test on the ecu side of the wiring plug and the meter beeped. On the sensor side the meter flashed a lot of numbers but no beep . Dont know if that means anything?

 

Did you clean the reluctor wheel at the same time? A faully sensor can also just be a dirty reluctor.

 

Hi daim, yes I gave it a going over with a wire toothbrush. I was hoping that was the problem as there was a lot of rubbish there from the time spent in the spray shop.

 

Did you get all the grooves? I had an issue like that on an older Rover 820. The ABS sensor wire was fine. The sensor too. It kept saying something was wrong but then just the pick up was bad.

Have you measured the sensor (resistance and co)?

 

I will give it another clean and have a measure. Not too clever with the meter.

 

I've had another go at this today but no luck. After a you tube tutorial I measured the resistance and all was ok. 1065 on the dodgy side 1048 on the opposite so the sensor is working? Next I spun both wheels and measured the volts. The good side gave a steady single figure reading. The problem side was all over the place, really chaotic figures. Presuming the sensor is good I polished the reluctor ring. No change in the readout still all over. I then tried to adjust the sensor without much luck. There seems to be very little adjustment and while there is no corrosion as all has been renewed I wonder if maybe some paint might need cleaning off in and around the sensor hole. Not 100% on what i was up against so After a couple of hours getting nowhere I locked up and came away. Any suggestions!!!

 

Swap the sensors over Brinny, and see if the readings go with them? Sounds like a duff sensor to me. But, then again, I know exactly nothing about ABS!

 

There are handed Greg so no go. Good thought though .

 

Buy a new one, Brinny!

 

It is. Well a new second hand one. Still dear enough.!!

 

Can you have a word with your French buddies Greg see if they have any ideas. They did invent it after All!,

 

brinny,

If I've read your thread correctly, you've performed blink tests with both the old and replacement sensors and got the same result?

As the blink test is performed at rest, it doesn't seem as if it measures the impedance to the reluctor ring (or else it measures it just at the one position at rest?).

So, the implication is that the fault lies in the wiring / plug connection / abs ecu. Or else the replacement sensor is also faulty?

I think you could determine if its the sensor or the wiring, by swapping the front 2 sensors and performing the blink test again. That seems a very easy thing to do. If the code swaps, then it's a faulty replacement sensor. And if the code stays the same, it seems to be the integrity of the wiring from the Right Hand Front sensor plug back to the abs ecu.

I know you said they are handed (and I'm not at my car until tomorrow to verify if that means wiring length or sensor orientation) but even if the blink test looks for an air gap between the sensor and reluctor ring (I'm not sure it does?) could you not just put the sensors in the holes even if they can't be bolted down, just to perform the test?

Good luck

Paul

 

Hi Paul, I'm happy that the lefthand side sensor is ok as the multimeter voltage reading was OK. The resistance on both sensors was virtually the same which suggests the righthand sensor is working. It didn't give a good voltage reading however. I wouldn't be able to secure it adequately in the other side to carry out a test. If the sensor is ok then I believe it is down to the air gap or the wheelbearing in my limited knowledge. When I rebuilt the front I gave everything a good coat of epoxy . I did notice that the sensor might benefit from the paint tidying up so to speak. I'm going to remove the top ball joint tomorrow to get proper access and make sure all is 100 percent. Is it worth checking the wiring back to the ecm for resistance? Should there be any? I did a continuity test and that seemed ok. I do know the air gap is very important and just a bit off can **** it all up.

 

Brinny
Again, as stated i have no knowledge of the system, but it seems to me you have found the evidence you need in the fluctuating voltage signal. What has not been pinpointed is the cause of it. Am I right in thinking (from your above post on the matter) the voltage you have measured is in the wires between the sensor and the ABS unit? If so, the obvious conclusion is that the signal being generate is the cause. And it could be that you are right about air gaps, alignment etc etc, but also that the sensor itself is faulty.

 

Yes you are correct Greg. Looks like a faulty sensor or its not generating a signal for another reason.