ATE MK70 ABS module repair

[tibia]

I have a Mk5 Golf with a MK70 ABS module (as opposed to the MK60 unit which seems to be more common on this model). It has developed the usual issue of no communications, lights on dash, no speedo, fuel gauge fluctuating, assisted steering affected. I am tempted to open it to check for bad solder joints or failed components. People have reported success doing this with the MK60 unit. Photos of the MK70 PCB indicate it is somewhat different. Has anyone successfully repaired a MK70 unit?

[tibia]

Just to add: I don't have my own access to VCDS. So perhaps a cheap option would be to obtain a working MK70 from a scrapyard and swap the EEPROM from my unit to preserve the coding. This assumes all relevant data is on the EEPROM and that it is not faulty or corrupt. Can anyone comment on the viability of this approach?

[Smiljan]

These guys have, I don't know if the info on their site is any use to you?

https://www.actronics.co.uk/acinsights/ate-mk70

[tibia]

Thanks. I had already seen this.Their article is interesting to read but not really specific enough for my purpose. Naturally, they are not going to post a detailed repair procedure on their public site. I was considering sending my module to them but their website mentions they won't deal with the public.

[tibia]

OK so I got the module off the car and looked inside. I knocked an electrolytic capacitor off the board while removing the lid - careless! I will probably use this as an opportunity to replace it with a new one. Nothing seems amiss so far. Only thing I have noticed is that I'm not getting 120 Ohms between either of the CAN pins and ground. I expected to see terminating resistors on the CAN lines. Maybe they are in the IC? Any ideas?

Edited by tibia on Sunday 12th January 20:16

[tibia]

Quick update. Capacitor replaced. Soldered connector pins since I had the opportunity. Tested with power on the board - everything as expected until I put power on the ignition switched pin - odd supply voltages to the chips and noticed the ATE branded driver chip getting hot. I guess the driver chip is failed and possibly other components but it is beyond my ability to test further. So I'm going to get an eBay module for 50 quid and either get it coded to the car or swap the EEPROM chips.

So does anyone know: is the coding stored in the EEPROM or in flash memory on one of the ATE chips?

[tibia]

Having read about this online, I don't believe coding the MK70 units is a problem so no need to pursue this plan of swapping chips. I will report back when I get to the end of this.

[tibia]

Final update: I fitted the second hand controller to my existing hydraulic block and without doing anything else, everything is working again!

To help others who may encounter similar problems:

The symptoms were:

• ABS warning light, steering warning light and MIL light on permanently.
• Brake warning light flashing.
• Chime and 3 warning beeps at ignition on.
• "Emissions Garage!" warning displayed at ignition on.
• No speedometer (or related functions).
• No increase in odometer reading.
• Fuel gauge erratic (dropping to zero when accelerating, overshooting when braking).
• Unusual throttle response (engine braking was quite severe, gear changes rough. Since the ECU must receive the car's speed from the ABS controller, various 'smoothing' functions which assist the driver were probably inoperative).
• Changes in characteristics of assisted steering: most noticeable one was the steering failing to self-centre after making a turn, nearly caught me out the first time it happened!
• ABS module failure to respond.

As you can see, the ABS module and the information it provides is crucial to many functions on the car!

The replacement module was from a 1K model which would appear did not have TPMS so the coding worked straight away.

It is possible to swap the electronic module without removing the hydraulic block or disconnecting any brake lines. The procedure (on the Mk5 Golf with MK70 and BXE engine) was:

• Disconnect and remove battery and battery box.
• Unplug MAF and remove air filter assembly (pliers to undo clip on air hose, one vacuum hose to undo, one torx holding it then it just pulls off).
• Remove battery tray.
• Disconnect electrical connector from the ABS controller.
• Remove the nuts which hold the ABS pump mount to the chassis to allow some additional movement.
• Remove three torx (2mm) bolts holding the controller to the hydraulic block. One is completely hidden from view which is the most challenging part.
• Once the bolts are removed, the controller simply slides away from the hydraulic block.
• Refitting is, as they say, the reverse of above!

Edited by tibia on Monday 20th January 20:52