Hi there..this is odd! Reset ECU and took the z for a drive ..All very good ;then, on a straight;very strange ...gave it some boost and suddenly the car is steering from the back and front just for a second I'm creeping sideways at 70mph!!...slowed down and stopped ,checked all wheels and tyres..headed off again and then again at 65mph did the same thing only this time on a corner!!Life of its own ...Any one with any ideas ..this car has never done this before ????? Rich

How did you reset the ECU? could it be possible that there is loose connections now, like were you playing with other electrics at the same time perhaps? Have you moved cables, or put some on top of other... like a stereo amp powersupply cable at 90degrees to a signal wire going to the ECU?

 

Below 20 mph and above 75 mph, the system is inactive, but between 20 and 75 mph, it moves the rear wheels up to 1 degree, depending on vehicle speed, steering wheel angle, and the speed the steering wheel is turned.

 

I am thinking that there is a cross signal happening, that somehow its picked up that 'you' have turned the steering wheel to its maximum.

 

It is a bit of a worry, as the HICAS system contains an emergency fail safe which locks the rear wheels in the standard fore-and-aft position if anything goes wrong, effectively turning the car back into a two-wheel steering system and the HICAS system doesn't seem to think anything is wrong.

Hey Rich, could it be that ur Boost starting to kick in,(as it hasnt been boosting) and u have not realised and started to drift the beast (like u n dave do with my z) as its giving lots of power and u r finally feeling the major power difference cos of the uprated turbos? maybe ur tyres that u bought are letting u down? Just an idea mate, let us know ;)

Hey and thanks for getting back with ideas... I disconnected the battery for two hours and detached the scart off the back of the ECU;reconnected the lot and was pleased to find this process has made the car run really smooth.did not touch any thing else,tho was cautious not to tighten ECU connection too tight..perhaps they are not tight enough?

Hey Rich, could it be that ur Boost starting to kick in,(as it hasnt been boosting) and u have not realised and started to drift the beast (like u n dave do with my z) as its giving lots of power and u r finally feeling the major power difference cos of the uprated turbos? maybe ur tyres that u bought are letting u down? Just an idea mate, let us know ;)

Tyres are fine ,wheel bearings are ok...Me drifting Lisa???I don't do that kinda thing to my car (only i would ,given half the chance, to yours hehehe)I'm going to take it out and test again ..see what happens

What year is yours? obviously if its a pre electronic HICAS then id say it is less likely to be that.

 

What condition are your shocks in, when i first had mine, one of the rear shocks was on its was out, and it had similar symptoms to yours

 

Nick

Did you notice any change on your speedo? I had similar symptoms when the speed sensor was playing up and intermittently cutting out the PAS/HICAS

Bantambunny had a similar problem , turned out to be a faulty Hicas unit behind the steering wheel :confused: :confused: