MY05 EHPS Steering rack replacement issues

[phoenix]

A friend at work asked me for help post replacing the EHPS steering rack on his car. He's fitted a used unit but there's no power steering assistance.  Initially there was an ESP error light but this has gone.

He's checked there is volts on the power connector, and I've looked at it via Tech 2 and there appears to be no communication with the control unit. I'm not overly familiar with using Tech 2 on the 9-3ss but it contacts the car OK (I can read other systems and values) but on trying to contact the PS unit it returns a message saying there's no systems available.

WIS suggests that it may need SPS programming via TIS2000 but surely it would at least need to be able to communicate.

Any ideas? Am I even going about trying to read any fault codes in the right way?

[sgould]

If it needs TIS /SPS then it will tell you.

[Audax]

Why was the unit originally replaced and have you checked the end to end wiring for the EHPS? You could try adding the module in Tech-II and see what it does. I dispute sgoulds suggestion that if something needs SPS programming that you will be told, most of the time the only way to see if an update is available is to read the data and then SPS to see what it says is available.

[phoenix]

Apparently the old one was leaking badly- it wasn't showing any fault codes though.

Just a thought- it also wasn't showing a steering wheel angle from the CIM, just an asterisk but it would seem from WIS that perhaps the steering angle on these cars comes from the EHPS unit. I'll get him to check out the cables.

[Audax]

WIS claims that the 1.9 with ESP uses steering wheel angle from the CIM, although, not sure if that is actually sent over the P-bus or not.

[phoenix]

Tried adding the module today but got an error message saying there was no comms with the ECU.

We're currently looking at one of two possibilities- the earth strap is missing, which could affect comms (although there is a ground on the two pin power connector) or the replacement he bought is duff.

[wrighar]

You should be able to 'talk' to the PS, on mine it will tell you angles, and current draw when turning (up to 70 amps!)