steering assist warning light on error

[cypher007]

ive got this error on 2005 A3:

00573 - Steering Torque Sensor (G269): Implausible Signal

ive checked and the torque value changes as I turn the steering wheel. my mechanic has noticed the steering is very tight when it was on a 2 post lift and he tries to turn the wheel by hand. so we found the top mount bearings seem to be binding slightly as the spring will turn then the top mount shortly after.

has anyone else found this error and found it was not related to a dead rack? I don't mind replacing the top mount bearings but not keen on a new rack. also if I get bearings which ones are good quality/value? I fitted some clone ones to my volvo 850 years ago and they were crap and caused lots of problems.

 

[cypher007]

anyone know if the ecu for the steering assist is also the abs one? e.g 1 ecu does both?

 

[ch1z64]

A quick search in google ( great tool ) found this worth using ( http://wiki.ross-tech.com/wiki/index.php/Category:Fault_Codes )
Especially if you have a genuine cable

 

[cypher007]

ive googled it and found that the steering ecu is separate under the steering wheel. so as ive had those covers off maybe ive knocked something ill check later.

 

[cypher007]

the reason I don't think the rack has gone is because when I bought the car it had this error before I started trying to fix its problems:

00829 - Heater Control Module (J162) 009 - Open or Short to Ground

I wonder when I cleaned the engine if the water has caused an issue or when I was fiddling with the dash ive moved some wires.

 

[Keram]

Your torque sensor or steering rack ECU is bad. Both of these are located under the bonnet, on the subframe.
Just try to delete the fault and see how fast it will come back.

 

[ch1z64]

Now that could be a big bag off worms opened but if you get a hold off a wire diagram it would help you trace the wires leading to and coming away from the sensor

 

[cypher007]

I had a google and seems the steering ecu is under the steering column. I’m going to try unplugging and plugging the connectors first. Then as ch1z64 suggests get the wiring diagram and have a look.

I have found if I delete the code whilst the ignition is on then got for a drive all is well until I turn the ignition off then on, then it errors after a short drive. After that it comes on almost straight away after turning the ignition on.

 

[Keram]

Good luck trying to unplug these connectors correctly on the car, as usually they are not easy to undo even on the table
Don't search for the wiring, here it is

Where B281 is the sensor and A81 is power steering ECU.

Unfortunately that won't help you, as you don't know what values to search on the pins 2-5, on the other hand you could check the circuit of this wire with multimeter, but to get the other end you have to lift the sensor cover, which is impossible on the car.

After ignition off/on cycle the system restarts all sensor checking procedure, so that's why you get the error back. But it's good you get it fast, because now your only option is to connect other, known good sensor and try to spin the rack and hope for no light on the dash. Then it's only a sensor and not a dead ECU. Anyway prepare to pull off whole power steering unit, or hope it's just a corrosion on the torque sensor connector (chances are 0.1%)

 

[cypher007]

What I don’t get is why when I watch the torque value in vcds it is changing by a fair amount - in one direction and + in the other. Surely if the rack sensor was knackered it wouldn’t change at all.

I might ask a guy at work who has a Skoda with the mk60 to let me watch the torque value on his to compare.

 

[cypher007]

By the way the power steering seems to be working fine other than the error light.

 

[Keram]

All of that is because there are actually 2 sensors inside (that's why 4 wires). Like main and backup one. System always relies on two, compares them, but if one is shot you see a warning light on dash and now ecu is working with only one of them.

 

[cypher007]

cheers for that info. that explains the reason im still seeing torque values in vcds then. I wonder if I can clone the sensor readings across to the faulty sensor? it would presumably fix the error.