Hi guys and girls, just had a new problem with 1.6 TDi 2010. Car judders and hesitant for a few minutes when driving...it only seems to happen when car warm.. ie short journey to shop. Restart and juddering starts when moving...the Speedo seems to judder but not with speed of car.. feels like it's is electrically dieing rather than anything else ...seems to clear up after few mins.. no dash warning

Just an update from a few mins ago - convinced its battery/alternator related. Sitting at idle and then switching lights on provokes minor engine hunting plus speedo starting to flicker plus some other strange behavious with the milage indicator - will take some voltage measurements tomorrow and keep you updated

Well a bit more info - I do have ABS warning on dashboard - but thought this unrelated. However, I noticed the problems seem to occur just after the anti-skid warning is displayed. So ignition on/start ABS warning, drive like 1-2 mins the anti-skid warning comes on and the hunting/speedo problems start. I know the speedo is some average of the wheel speed....so its really pointing to ABS problem - plugged in the Carista dongle and both front and rear L/H ABS sensors faulty.. could it be the system is trying to match wheel speeds hence the hunting behaviours...before deciding the abs sensor is faulty... anyway Im going to replace both sensors

How old is the battery and what voltage is it when car off and cranking and running. If the voltage is ok check terminals/earths for corosion. It may be that when car is warm something like a corroded terminal/bad connection etc is causing voltage drop and puting up random faults when heating up.

Seems unusual that both front ABS sensors have failed together? Anti skid warning and steering wheel warning come on when battery is disconnected so if the voltage is dropping too low they may come on.

Alasdair

Anti skid warning comes on with no signal from a wheel sensor. One of the sensors (which I thought was rear-right) is used for the speedo. So first action is to check the ABS wheel sensors and rings.

Thanks for replies - Batery voltage and charging are good - getting over 14V charging at the battery. I agree It does seem weird to loose both speed sensors at same time - I reset and L/H front failed immediatly a short drive and L/H rear failed. So Im going to replace both and go from there.. Will update later

Edited 24 July24 Jul by oj17

Sorry I am sure I read battery light was on. Been a hot few days. Hopefully sensor replacement will cure problem.

Alasdair

Guys, again thanks for replies - I replaced both front left and rear left wheel speed sensors and all seems fixed. Its only been a couple of short drives but no problems so far. I feel I quite tech savie and have formal training as a fast jet avionics tech. but it is so easy without having all the facts to go down a rabbit hole... FYI I spent a bit of time on part numbers... and here they are

wheel sensor	OEM	GSF Hella part number
FR	WHT003856	HEL6PU 012 039-021
FL	WHT003857	HEL6PU 012 039-011
RR	WHT003858	HEL6PU 012 039-041
RL	WHT003859	HEL6PU 012 039-031

anyway I know I could probably get parts online cheaper than GSF - but wanted to get the job done and they have a good returns policy.

Thanks again for the help - PS ITS A T30 star drive for the wheel sensor bolts!

Been using https://www.partsinmotion.co.uk/ for a good while now and normally 48hr delivery and I am in Inverness. Reckon quicker if you are nearer. Prices so far cheaper than most and do a good range of decent quality aftermarket parts.

Alasdair