Wheel Speed Sensor Problem...... again!

[Westy]

I had my right rear wheel speed sensor pack up in January so I replaced it with a sensor from Euro Car Parts. All was ok till about a month ago when the sensor stopped being able to read speeds under 5kph and decided to engage my ABS pump when I was crawling along!

Anyway 4rings came and diagnosed the issue and suggested that I bought a genuine Audi sensor to replace the euro parts one. I replaced the sensor this weekend and got about 10 metres down the road before my ESP and ABS lights were flashing at me! I plugged in my trusty VAGCOM and logged the sensors activity. As you can see from the log below the sensor doesn't pickup any signal till about 43kph then it goes nuts and starts reading random speeds!!!

I spoke to Audi about warrenty on the sensor if I can prove it is faulty by swapping it over with my working left rear wheel speed sensor. I was told that their mechanic will have to diagnose if I want the part replaced as I had fitted it myself. $$$.

I am planning to swap over the left and right sensors this coming weekend to see if the problem follows the sensor. If it doesn't then I'll be heading to the stealers for a wallet beating.

Does anyone have any experience with these sensor problems? Could I have a faulty part or is it more likely to be the rest of the wireing?


Here's the log:

 

[ash_pearce]

just a thought but is the actual abs ring ok? not got crap stuck in it? I'll be changing mine at the weekend with some parts from gsf. Had a look last weekend to remind myself how difficult or easy it might be and had half a field stuck in mine.

 

[Westy]

just a thought but is the actual abs ring ok? not got crap stuck in it? I'll be changing mine at the weekend with some parts from gsf. Had a look last weekend to remind myself how difficult or easy it might be and had half a field stuck in mine.

Have you been offroad or something?

Thanks for the idea Ash but my ABS disc was in good nick which is whats pointing me towards a wireing issue further down the line.

 

[ash_pearce]

i think the previous owner did everything they could to ruin my car. the joys of an ebay buy haha.

Is looking like some form of wiring issue then, wd40 in the connections then and check the fuses might have one not seating quite right. good luck mate.

 

[Westy]

Anyone else got any input?

I'm going to be swapping my working rear left sensor for my dodgy rear right sensor tomorrow to see if the problem follows the sensor or if the problem is with the rear right wiring.

Does anyone know where the wiring goes, iirc someone once said it came up ito the cabin under the front seats?

 

[ash_pearce]

I did mine last night, I had a rear right fault in vagcom. Replaced with a cheap part from gsf, then vagcom reported rear left, put the so called 'dead' sensor from the right in the left.

Guess what both popped up, with 01276 abs pump, did some googling and found that it is a common problem, some people reporting a new abs ecu some saying new abs pump is needed.

I checked the fuses on top of the battery, all good same voltage across the board.
Next unplugged the abs ecu (attached to the pump) gave the plug a blast with some circuit cleaner, problem solved

sorry for the essay but thought i'd let you know my outcome in case you have the same problem.

 

[Westy]

Cheers Ash.

My fault says faulty sensor as apposed to any ABS pump fault!

The annoying thing is if it is a faulty sensor Audi wont replace it until their engineers have looked at it and I think that an hours labour at Audi costs more than a new sensor!

 

[Westy]

Ash did you check what your wheel speed sensors were doing like I did above? Just wondered if your ones were completely dead or giving sime signal.

cheers

 

[ash_pearce]

If they can make money out of you they will, seems unfair as its a genuine part. Hope you get it sorted mate.

 

[ash_pearce]

Ash did you check what your wheel speed sensors were doing like I did above? Just wondered if your ones were completely dead or giving sime signal.

cheers

no i didnt, still learning vagcom what block did you read?

 

[Westy]

no i didnt, still learning vagcom what block did you read?

Number 1 and you should get what I got above. All 4 speeds for the wheels in KPH

 

[ash_pearce]

I'll check mine later, this might be the answer i've been looking for as regards to my speedo being out. (http://audi-sport.net/vb/showthread.php?t=71620). thanks mate!

 

[Westy]

I think your speedo/revs will read data from a sensor on the gearbox. As far as I'm aware the wheel speed sensors are only used for ABS and haldex but by all means have a look at the data they are putting out in VAGCOM.

 

[ash_pearce]

I think your speedo/revs will read data from a sensor on the gearbox. As far as I'm aware the wheel speed sensors are only used for ABS and haldex but by all means have a look at the data they are putting out in VAGCOM.

It does but I think my speedo needle is out so if i can read the speed from the wheel sensor and get the mrs to read it off whilst driving at a set speed hopefully i'll know how accurate my speedo is. thanks for your help mate.

 

[Westy]

Just remember the wheel speed sensors are in KPH just incase you think you'r going quicker than you actually are

 

[ash_pearce]

Just remember the wheel speed sensors are in KPH just incase you think you'r going quicker than you actually are

lol can just hear the mrs saying slow down your speeding.

 

[Westy]

I managed to fix my problem on Saturday. I spent 2 hours trying to get the working sensor from my rear near side wheel out to swap it with the off side but it wouldn't budge. I didn't want to damage it getting it out so I decided to give up and take another look at the faulty one.

One I had the brake disc off and took a look I imediately spotted why it wasn't working properlly! I hadn't fitted the sensor close enough to the ABS spindle. The working one was only about 4mm away from the spindle where the faulty one was about 10mm away!

I got under the car and hammered the sensor into its hole a bit further put everything back together and went for a spin. All my dash lights went out and have stayed out, i'm well happy now.

 

[ash_pearce]

glad your sorted mate! Finally got round to checking my speedo against the speed readings from the abs sensors, quick adjustment on the needle now reading correctly.

 

[Westy]

Excellent news mate, I'm now waiting for the next thing to fail! Out of interest, how did you adjust the needle?

 

[ash_pearce]

Excellent news mate, I'm now waiting for the next thing to fail! Out of interest, how did you adjust the needle?

with the facia out of the dash the clear plastic part on the front comes off the back leaving the needles exposed. Carefully moved the needle with my fingers, bit of trial and error though kept moving it too far.

I know what you mean, every week something else pops up on mine, so much for a 'good buy' lol!

 

[Broken Byzan]

I got under the car and hammered the sensor into its hole a bit further put everything back together and went for a spin. All my dash lights went out and have stayed out, i'm well happy now.

I think the technical VAG term is adjusted...... LOL

 

[Westy]

I think the technical VAG term is adjusted...... LOL

Oh yeah! erm I meant to say that I gently eased the sensor into its normal seated position

 

[Biggied]

Thats why your dealer wanted to check the car first before replacing anything under parts waranty, some planks out there would fit the sensor incorrectly then try and claim there brand new part was to blame , its a tuff old game.

Ewan