Fabia 1.4 16v 100bhp, AUB, X plate, Elegance.

Had all the three lights for the ABS, ASR, and the handbrake light all come on with the beeping sound whilst driving down road!! Pulled in and switched off ignition then pluged my code reader in (it lives in the glovebox) and it said "unable to communicate with ABS controller!! So I then went into the main engine ECU and it showed up only one fault code which was "unable to communicate with abs unit"....I then went into the instrument cluster...and it only had one fault code.....you guessed it "unable to...etc". Started car up and lights remained on! Brakes work ok fluid level ok etc.!

Only done quick check so far:

The fuse on the fuse board has power to it and is ok

The fuses on the top of the battery are all ok

The main plug on the abs unit is ok and the pins look ok with no corrosion!

I will be doing a full test on the wiring later on.

Has the wiring on the power side broken, or is it the CAN-BUS wiring from the ABS unit, or is the ABS unit FUBAR???? :(

Couldn't find this problem in the tech or other sections (so far)....has any one had this happen to them.....was there a "best place" to start looking that would be the cause?

Edited 22 May, 201115 yr by fabdavrav

Root cause is no comms with ABS controller from the OBD2 port, hence why the ECU can't see it either. ABS units can get water ingress once the foam seal cracks, and it's new ABS unit time.

Had this all through the freezing months. Turned out to be weak battery. Missing signals etc, total loss of power steering to.

Edited 22 May, 201115 yr by Fabla

Right then....I've done a more fuller check on the wiring....at the ABS unit plug I have correct voltage on all the lives, correct switched voltage, correct earth, correct resistance for sensors, also small amount of voltage when ignition is on for the CANBUS wires, the fuses on the top of the battery are all ok, and if I unplug the ABS unit there is no shorting (no voltage)....so all as it should be!!!

My questions now are..

1. I have heard that it could be the steering angle sensor (I still have the old plastic covered one, not the metal version)......but as I have no PAS problems or lights....or flickering etc.....is this ruled out????

Just done a scan of the Steering ass' ecu (block 44) and there are no fault codes stored!

2. I have also heard about a wire by the alternator??? which might be causing it????

3. Shall I just admit defeat and send the ABS unit off to see if it can be re-used??...(and if not then just bin it and get new??? Bugger!!!)

4. If the ABS unit cannot be communicated with by the instrument cluster, the engine ECU, and the code reader...then how does the speedo work???? I thought it used the ABS sensors for that!!???

Still have the following fault.

Had all the three lights for the ABS, ASR, and the handbrake light all come on with the beeping sound whilst driving down road!! Pulled in and switched off ignition then pluged my code reader in (it lives in the glovebox) and it said "unable to communicate with ABS controller!! So I then went into the main engine ECU and it showed up only one fault code which was "Powertrain failure...unable to communicate with abs unit"....I then went into the instrument cluster...and it only had one fault code.....you guessed it "unable to...etc". Started car up and lights remained on!

Edited 27 May, 201115 yr by fabdavrav

SHOULD BE SOLVED!!!!

I've just had the bad news from BBA-Reman. They did their checks on the unit (their diagnostic equipment is better than VAG) and then they opened the box up and no broken "jumper" wires, no water damage/ corrosion, no "burnt" components on PCB etc. etc.!!!! So they think that a component (chip) has "failed" with no visable sign!!!! So the PCB is FUBAR and replacements are N/A!!! So as I said they can keep it (bin it) there is no charge to me for the testing & collection! New units only are avaliable from Skoda..so this is what I'm getting....don't want to risk £250 for an EBay unit etc....Eurocarparts want over £1,000!! Will get a slight discount from my local Skoda dealer, but still near £1,000!!

Now I just need to re-code the new unit to my car when I get it!!! I hope that this is easy to do...I have a unit that will do it but need to do some research into the procedure!!! Anybody done this????

P.S. My local Skoda parts bloke thinks I did very well in getting 10 1/2 years out of an ABS unit!!!...apparently most people are well into their second unit!!!

Edited 6 June, 201115 yr by fabdavrav