Also my MOT today!

[urquattr085]

Well I got my timing a bit wrong, MOT doesn't expire for another couple of weeks, but have it booked in for next Saturday.

Anyway, a good result today while doing pre-MOT checks.

Been fiddling about with the abs sensors for months in a vain attempt to resolve the familiar "abs light comes on after a few hundred yards".
Knowing they were all working it had to be just a matter of sensor position relative to each other giving varying output signals, but no matter how much I tried, just couldn't sort it.

Happened to acquire an oscilloscope last week for the grand sum of a box of 6 real ales, hooked it up this morning to each sensor and BINGO, 2 hours later, no abs light. Both front sensors were giving very weak signals in comparison to the rears.

So chuffed, I took the car for an Italian tune up

[Mellis46]

Originally Posted by urquattr085

Happened to acquire an oscilloscope last week for the grand sum of a box of 6 real ales, hooked it up this morning to each sensor and BINGO, 2 hours later, no abs light. Both front sensors were giving very weak signals in comparison to the rears.

So chuffed, I took the car for an Italian tune up

Nice Mine very occasionally throws the light, on my 'to do list' is to check the reluctor rings on the driveshafts. Was it literally just a case of moving the sensor positions which the oscilloscope helped you nail??

[urquattr085]

Hi Mark

Yes, pretty much. Haven't had reason to disturb the rear sensors, so hooked up the scope to osr connector, spun wheel slowly and noted the output, did same on nsr and got same output. I then used this reading as a reference point for the fronts.

The front suspension/brakes have all been worked on and were prime suspects for causing the fault.

Output on both front sensors was none existent so removed both and passed a screwdriver close to the tip to confirm wiring continuity and sensor was functioning.
Both gave strong results so replaced and then tapped in bit by bit, checking output each time until I got a similar reading to the rears.

Worked a treat for me, a bit trial & error to set the scope up but then again, I've never used one before and​ soon figured it out.

I can let you know what settings I used if it would help.

Hope this will help you or others out with the same problem.

[Mellis46]

i don't have a 'scope but maybe i need to be on the lookout for one

[urquattr085]

Mine is similar to this

http://www.ebay.co.uk/itm/Oscillosco...YAAOSw~iRZov4e

I guess any that can measure millivolts would be ok but I'm no expert!

[sinbin5t]

Sounds like you're ready for a pass now.

[urquattr085]

Hope so, cheers.

[sinbin5t]

Originally Posted by urquattr085

Hope so, cheers.

Fingers crossed for you mate

[urquattr085]

Ta, I'll keep you posted.

[urquattr085]

So Saturday came and went, no MOT (boohoo!!!!).
Got to my regular test station and the guy had a fully loaded transit on his ramp with a failed immobiliser and a box full of wrong parts.

Needless to say I was soon on my way back home.
Upside - it's a great (read as quiet and twisty) road to get there

So he picked it up from my workplace today, got a pass and no advisories - happy days.

Off the road for the winter at the end of this month with quite a bit of work planned ready for the Spring.