ABS/ ASR - Another one with problems!

[tristanlj]

From my searches, I see there's a fair amount of issues in this area. So here's mine.

I have the NO ASR, EBD and ABS warning lights on constantly. I've taken the car to Dick Lovett to be diagnosed - which they kindly did for free and it's showing an error on the Rear Right. Mines a 2001 3200 model so doesn't have the ODB reader on the ABS unit itself so it talks directly to the ECU.

I guess the good news is that the ABS ECU is talking to the main ECU so therefore isn't faulty (I hope!). The bad new is that they think it's a valve within the block which is faulty and the whole block, including ECU needs replacing. They want it back in to run further tests on the wheel sensor and other electrics to rule out everything else first.

I know that the ABS ECU and valve block can easily be separated so is it possible to just replace the valve block? I see from the service manual that replacement blocks come already loaded with DOT4 so will this cause an issue? And will I need an SD2 to bleed the system?

I tried checking the sensor myself but could get the brake disc off due to a sticking handbrake. Once that's sorted, what am I looking for when I unbolt the sensor? All wiring to the sensor looks very clean and sound.

Many thanks in advance for your help.

Tristan

 

[Parisien]

Tristan welcome to our forum.......am sure one of the old hands will pass by and help out.


P

 

[hodroyd]

Hi Tristan,

Welcome to the forum. I am not an old hand, but have you tried disconnecting pins 1 & 2 from the control unit, which are the right rear sensor connectors, just to see if that takes the lights off? Pins 1 & 2 are on the right hand side of the long row of pins, when the long row is on the bottom.

Cheers
R

 

[tristanlj]

I haven't tested those as yet but I would have assumed the error would still happen as the ECU would see the rear right as missing. Should a continuity test on those two wires come back with a complete circuit? I suppose I can test that myself with wires 4&5?

 

[hodroyd]

Yes you could test pins 1&2 to see if the circuit is open, or closed. Someone else may know more if you want to hang on a while.

 

[ENZ525]

Hello Tristan,
Welcome to the forum, sorry can't be much help with your questions...
Only one I have an inkling on is that I believe you will need sd2 to bleed the system ( I am not 100% sure though).
Regards,
Enzo.

 

[tristanlj]

OK. I think I have some good news... I think! Maybe someone out there can help out.

I unplugged the connector into the ABS unit, turned on the ignition and tested the continuity of pins 1 & 2 (right rear wheel) and it gave a continuous beep meaning the circuit was closed. I then tested all the pins for the other wheels and they all had no beep - no circuit. My assumption is that the RR sensor is faulty. Can someone out there with a more electronic mind confirm that I'm making a safe assumption? It will be an incredible relief if it's just the sensor rather than the block at fault.

 

[hodroyd]

OK Tristan, if those are the results, I would suggest that your RH sensor has a short circuit giving you a closed circuit. I am pretty sure this will be your problem and you should replace the sensor. Does it look damaged? It might have just failed and now gives a continual short. For the price of a sensor I would go that route first.

Cheers
R

 

[hodroyd]

Tristan,
One other thought, when you have disconnected the sensor, just check the circuit again, it might just be the cable for example?

Cheers
R

 

[tristanlj]

Grrrr. After spending an age trying to unstick the damned brake shoes in order to get the damned disk off to get to the damned ABS sensor, the damned bolt holding the sensor in **** well snapped!! Bolt removal tool is on order...

 

[hodroyd]

Hi Tristan,
Testing your patience then, they do that sometimes, it's an Italian thing.
You could try drilling out the old bolt and then fitting a new one, if you can get at it.

Cheers
R

 

[rs48635]

Good luck with this - you do right to jump on it early. A sensor fault will quickly escalate into a failed ABS unit.

Just to clarify, which ABS light was on?
Think there are two ABS lamps, one for the sensor only.
The second ABS lamp of for the main ABS unit, which also turns on the NOASR lamp. In the past this scenario has proven fatal for most 3200 ABS units.

You may have a new scenario, or new symptoms, so please keep track of what goes on.

btw I have access to the service manual (electronic copy), so could get the resistance values for the sensors, think 1-1.7 k ohms. Do you have an electronic multimeter?

 

[tristanlj]

It's the complete lightset which has lit up, however, I have a theory from reading about other ABS ECU failures that this only happens to pre 2001 models without the OBD2 facility. They've all mentioned that the failure comes from a communication error onto the CAN and a failure to talk to the main ECU (I'm no expert!). The errors on my car can be read correctly via an SD2 unit and it had pointed to the rear right, which from my own checks proves to be correct. This, I am hoping, means that my ABS ECU is working fine and dandy. Time will tell once I eventually get it replaced...

 

[hodroyd]

Keep at it Tristan, you will get there and finally cure it.

 

[rs48635]

Update on my ABS - after 2nd unit fitted. I have all ABS error lamps off now : D

There is still some 'pulsing' or abs grumble under light braking. Will reserve judgement until I have fitted the new front disks. Waiting for full set of green grippers to arrive, to avoid doing the job twice. Kills me every time I go into the garage and see those beautiful shiny big disks on the work bench.

Sending back both 'faulty units' , for ECU to be sent to USA for repair. Will let you know progress, as these would be the first successful ABS ECU.
Original faulty unit is normal part number 383800316 (same as Eurospares)
1st spare is 383800315

Anyone with an early car got a 38300315? Easily spotted on top of unit, rearmost toward bulkhead.

 

[bill]

Thats what mine did Rob, especially at high speed, it felt like a slight on off on the revs even with out applying the brakes as its the same unit that controls the traction. it turn out to be dirty phonic wheels at the rear. did you get an "ECU error" on your faulty units on the SD3? who have you used? I have sent my faulty ones to so many places (all over the world!) and the all said they cant repair them so I will be interested to find out if you have found someone that can!

cheers
bill

 

[hodroyd]

Very interesting information, we all eagerly await the outcome.

 

[Contigo]

No ASR and ABS light have come on mine now, always the way before an MOT isn't it?

So what is the main thing to do now? Check each sensor? Any other checks? Resistance at the sensors?

 

[hodroyd]

To save time get the codes checked on an SD2, that should pin-point it..!! Could be a skyhook sensor..??

 

[Contigo]

Can't get to an SD2/3 this week as nearest is Mike Roberts really. I will try to read the codes myself on the UniDiag and do a visual inspection.

I don't think this points to the Actuators it is more than likely the dreaded ABS ECU failure

Thanks Robert!