ABS light on & won't go out!

[blue harbour]

As per title my car has developed a fault on the ABS system somewhere and now the ABS light is permanantley on (when driving the car!), We have had the wheels off and popped all the sensors out and cleaned them and also looked at the reluctor rings for signs of damage to the teeth etc, but they all seem fine, We were also adivsed that we could use a multimeter to test the sensors to see if they are Ok (test them for resistance) and all then sensors had the same kind of resistance to them too!

We have also had a quick look at fuses and at the ABS modulator block assy to see if there were any obvious broken wires/loose connections but there was nothing obvious so were now stuck as i think we've exhausted all the DIY checking routes we can go down so my question to you peeps is "What next"??

Am i now at a point where i'll have to bite the bullet and take the car to a specialist to get the fault codes read that the system should have logged or is there anything else we can easily check?? (there's nothing "obvious" that we can see!!)

Fyi I "think" the fault occured coming back from this years Festival of Speed at Goodwood (can't be sure as i wasn't driving at the time) we were just getting close to Tamworth services and hit a bad pothole on the M/way (went with a pretty loud "bang"!), and i am assuming this will be when the ABS light came on after we hit the pothole, but as my cousin was driving at the time (we'd split the driving duties, and it wasn't till i got back behind the wheel when we swapped back at Tamworth that i noticed the ABS light on!)

I have a horrible feeling this is gonna cost £££'s to sort as nothing we've done so far in terms of maintanence or repairs has been cheap with this car!!!

What really gets me is - if it wasn't for this we'd have had a fantastic/trouble free weekend with the Esprit - it'd been surprisingly very good on fuel (for a V8) and we'd covered a lot of miles going down to goodwood n then trekking from the campsite n back Sat/Sun n then we went a trip down the coast on the monday n went to Bournemouth for the day to finish the weekend of in style! We were MOST of the way home too when the fault occured - just to put a dampener on the whole thing!

Is it ANOTHER trip to a specialist then ?????

Edited August 14, 2011 by blue harbour

[oneshot]

Certainly anyone with a Lotus Tech1 should be able to read the ABS fault code. I think, however, you will find that only Lotus dealers have these. I certainly had mine read by the dealer when I had the ABS light on and it immediately highlighted which sensor was faulty.

Sparky had a reader at Supecar Sunday which we hooked up to my car but from memory I don't think it was capable of reading the ABS codes, only the ECU.

[Dave Hopwood]

Hi,

If the fault occurred after you hit the pot hole I would suspect the reluctor ring on that wheel has moved.

The sensor coil has to be within a certain maximum distance from the ring in order to obtain the correct amplitude.

If you know anyone with an oscilloscope you can compare the the outputs of the wheel sensors

Some multimeters will give you a fair indication on the lowest AC Volts range

Another indication of it being a sensor problem is if the ABS light goes off after you start the car then comes on as you start to move off

Regards

Dave H

[blue harbour]

As an end to this and for anyone who's interested the car was shipped off to Peter smiths for this fault to be sorted aswell as a knackered starter motor, and it turns out it was the ABS unit itself that was knacked!

Ended up having a bill for nearly £4k for a replacement stater motor, new ABS unit and replacing a pair of outer rear CV boots that had split!

Seems like even simple jobs with what you'd think would be cheap parts cost ££££'s to put right with this car (ABS unit being the exception - yes!)

[Sparky]

Ouch! Praying I don't have to go the same way. My GT3 ABS light is permanently on (from startup). However, I've swapped the unit with Chris's (internets) good one, and my light remains on, whereas my unit on Chris's car gave no fault. Haven't got around to getting a Tech1 on it yet...

[sailorbob]

I heard today from a Lotus mechanic that the V8 starter motor is obsolete and unique to the V8. Maybe you got one of the last ones!

[jcbjs 260]

I had the same problem,checked everything but the light stayed on. I was working with the car stationary all the time in the garage. Make sure when your testing the system you take the car for a short test run to reset the abs