Heavy Steering issue - Servotronic

[Craig Norquay]

So, got the car back after having it's front end respray to tidy it up, Mrs drove it home from the paintshop and when we got back, she mentioned steering was really heavy.

I thought it was due to her not driving it often, so I jumped in it and right enough it was like the car had put the steering to the heaviest possible while still maintaining power steering.

Checked fluid levels and was all fine, turn it off and on again a couple times then suddenly, the steering became light like it should be stationary.

Ran a scan of the car and it gave me Solenoid valve for servotronic as a fault. So whats the script, anyone had this before and is it an easy fix? I'll keep an eye on it as it may have just been down to it sitting for best part of a week without it really being used.

 

[SteveMcB]

Don't know anything about solenoid valves but does sounds like it could be the servotronic relay sticking, happened to me, power steering still works but stops the extra low speed assist.

Mine was affected by temperature, i.e. if it was cold it wouldn't work. After 10 minutes or so I could recycle the ignition and get it going again. If I kept the relay in the house overnight it also worked fine, didn't throw up any fault code as far as I recall.

It's a small black box about an inch square and 2 inches long with a white number on it, mine is 640 (part no 8eo907307D0). Plugged into a bar beside a few other relays on the driver's side above the pedals, you'll need to remove the trim to get access but on the b7 it's only a couple of screws.

There's quite a few different numbered modules, AFAIK they all do the job but have different characteristics, i.e. some give more assist than others, S4 is probably towards the heavier end of the scale ( I thought about getting a used one off eBay) but eventually got my warranty people -RAC- to stump up for a new 640.

It was probably nothing more than a dry joint but the internals looked very complicated (to me anyway) so I didn't investigate further.

New they are around £120, which seems a lot for what it is but it is an easy fix. Hopefully your's is a one off but if it reoccurs there is a thread on here somewhere.