Strange ECU/BCM fault VP Calais

[VR38]

Hey there,
I have an ongoing strange ECU/BCM electrical fault in my VP Calais that rears it's ugly head after a steering shutter.
Car will run virtually faultless till I turn in quick (the steering wheel) in a corner and the steering rack shutters.
Soon after the variable assist on the power steering fades away and the rack resumes normal power steering and I notice the engine gets a little less responsive and an ever so slight miss.
No other electrical or mechanical issues noted.
Now the car is still quite drivable and would have no problem driving around anywhere any distance but it is so noticeable to me the change in the engine and also to anyone the change in the steering input.

Thing is, if I leave the car with the battery disconnected for over a week (a BCM reset or a quick disconnect and reconnect does not fix it) the car is as good as new, sparking the rears just breathing on the throttle and the steering is like a hot knife in butter... till the steering rack shutters again.

Will be fitting a new rack and variable steering switch soon but would like to know if anyone knows what is going on and why the steering fault is affecting engine performance?

 

[hi_ryder]

..............................

 

[hi_ryder]

trace the 2 wire loom that runs from the rack to the cluster of plugs near your fuse box. might be a good idea to check for exposed or worn shielding, extractor melts ect... could be earthing out on turns or something.

when i bought my calais one of the wires was connected with a household wire nut with exposed copper showing.... lol actually still is gotta fix it....

 

[VR38]

Buy WHYYYYY does it affect engine performance?????

 

[hi_ryder]

might be loading the engine when the solenoid trips on and off, causing the rpms to hunt? not sure dude.

 

[VR38]

Yeah, was bench racing it last night and feel it maybe pump load related over an electrical problem.
Thank you.

 

[sidecar55]

Check the pump out. I've seen a variable type pump that had plastic bits through it. There's something in them that collapses, gets ground up & goes through the system.

 

[VR38]

Sorry, the pump it's self is different?
I was under the impression only the rack itself is different and the pump was the same across all models standard and variable?

 

[sidecar55]

I think it's something in the rack that works way into the pump.

 

[VR38]

There is no connection.
The only thing I see different is the variable switch connected to the rack.
AFIK it is solenoid controlled pin with holes in it that slides up and down to control flow.