Steering Angle Sensor of doom..

[N1CKY]

Hi All, I'm asking on the odd chance someone may be able to help with my strange fault.

 

2003 4.5 Turbo

 

Original fault was no comms to loads of different modules, air suspension, gearbox, front diff etc. The sunroof drains were blocked, water ingress in the carpet which coupled with a tiny hole in some insulation on an Ignition relay terminal 15 feed made that it wasn't  powering up. That is now fixed and I'm stuck with one fault. No modules can communicate with the steering angle sensor, it immediately returns a defective status when cleared in the abs/stability control modules.

The sensor is driven directly from the steering wheel control module, which I can communicate to. But it passes a separate 'drive' can link through to the sensor where the steering module is on the 'comfort' can bus.

The steering wheel control module has its terminal 30,31 and 15 voltages as it should. The drive can bus resistance checks back to all the other modules (I don't have a scope handy to check the integrity of the bus but i presume its OK as the rest of the modules seem to communicate OK)

 

The sensor and steering wheel control module have both been swapped with known good units. Fault remains.

 

I tried the Porsche specified calibration procedure with no luck, I don't have access to PIWIS but i am communicating with the car using VCDS as its essentially a 7L Touareg

 

Does anyone have any ideas?

 

Thanks in advance. 

 

 

[JFP in PA]

Yes, you need the PIWIS.

[N1CKY]

22 minutes ago, JFP in PA said:

Yes, you need the PIWIS.

 

Hi, Thanks for the reply. What makes you say that? Will it do something specific that VCDS wont?

Thanks.

 

 

[JFP in PA]

15 minutes ago, N1CKY said:

 

Hi, Thanks for the reply. What makes you say that? Will it do something specific that VCDS wont?

Thanks.

 

 

 

Yup, reactivate (assuming is it salvageable) and re calibrate the module in question.

[N1CKY]

3 minutes ago, JFP in PA said:

 

Yup, reactivate and re calibrate the module in question.

Im not sure what you mean by reactivate, Iv never seen a module needing 'activated', only coding. But i cant communicate with the module anyway, not even to perform a calibration which i thought should of been possible in VCDS for sure considering its a VW part. But if you have experience that says VCDS specifically cant do it on this vehicle i will seek to find someone with PIWIS.

 

 

[JFP in PA]

6 minutes ago, N1CKY said:

Im not sure what you mean by reactivate, Iv never seen a module needing 'activated', only coding. But i cant communicate with the module anyway, not even to perform a calibration which i thought should of been possible in VCDS for sure considering its a VW part. But if you have experience that says VCDS specifically cant do it on this vehicle i will seek to find someone with PIWIS.

 

 

 

While the vehicle may contain VW parts, some of them are running Porsche software, which the VCDS cannot even see.

 

Sometimes these modules drop offline when there is a water short, assuming it is not totally dead, the PIWIS should be able to see and communicate with the module, bringing it back online so it can be calibrated.  If the PIWIS cannot communicate, you will need a new module, which will need to be coded to the vehicle, which the PIWIS can also do.

 

Just remember, the 911 and Boxster vehicles also carry VW components, but the VCDS is useless with them.

[Niklas 71]

Have you used a rewired cable between your car and the VCDS interface, with pins 15 and 3 connected? At least I think those were the pins needed to allow VCDS optimum acces to Cayenne sub-units. 

[N1CKY]

3 hours ago, Niklas 71 said:

Have you used a rewired cable between your car and the VCDS interface, with pins 15 and 3 connected? At least I think those were the pins needed to allow VCDS optimum acces to Cayenne sub-units. 

Pins 3 and 7, yeah I did. I can communicate with all the other modules just fine. 

[N1CKY]

Just to let you all know, you were right. I needed a different diagnostic tool to recalibrate the steering angle sensor. I ended up using an autel system which I can reccomend thoroughly! Many thanks. 

[JFP in PA]

3 hours ago, N1CKY said:

Just to let you all know, you were right. I needed a different diagnostic tool to recalibrate the steering angle sensor. I ended up using an autel system which I can reccomend thoroughly! Many thanks. 

 

😉