I think this does fix the PS as well I have the same problem, so let me start by thanking you for posting this info. The reason this would fix everything is because the speed sensor on the gear box sends the signal to the cluster/speedo which gives you your speed, it is then fed back to the ECU from the speedo. When the connection is poor/lost the ECU goes into a "worst case scenario" and assumes the car is travelling past max speed, which makes the steering go hard as you will notice with the zed the steering get harder the faster you go (considered a feature), not really noticable until you reach much higher speeds though. So by fixing the connections you are elliminating both problems (as they are related).
my power steering only ever dropped out when the speedo played up. So far I have had no problems with the speedo and none with the power steering. Since the power steering is power assisted(function of speed) I have always presumed the problems are related. I know for a fact that when the speedo plays up the ECU is receiving the incorrect speed. I never quite understood why when the speedo was at 0 the p/s cut out completely as this is when you should have full assistance. The *worst case theory-scottZ post* is the first explanation I have seen that is plausible, with out knowing what the ECU does with the data who knows... Given this descrepancy, it is quite possible the a-p/s problem is not fixed, 2 weeks might be a bit premature. Will post if I have any further problems with p/s or speedo. good luck mal
Re: my power steering only ever dropped out when the speedo played up. The speed sensitive steering has only two sensitivities. There is only a soleniod that selects that. So it is not continuously variable only swaps back and forth at a certain speed.
was just looking in the z32 manual as one does and noticed Z32 Service Manual, page ST-31, extract 'The power steering system is a twin orifice type, which uses a vehicle-speed sensing, electronic control design. Valve sensitivity is controlled in response to vehicle speed to achieve optimum steering effort. When a vehicle-speed signal is not entered into the power steering control unit for approximately 10 seconds during normal operation, a fail safe system activates to maintain the steering effort at a level similar to that experienced during high-speed operation'.... doesn't this imply more than on off?
if u don't already have your answers you may wish to look in the Z32 service manual in particular section ST-31 and also ST-39. Page ST-31 gives a good break down as to how it all hangs together.
Re: speedo I just want to add - I have the same problem. Irratic or 'zero/max' speedo and the power steering goes heavy. I think it was abit unintelligent to source the speeds for the ecu from the instrument cluster. Would have made more sense to just recieve it straight from the gearbox, eliminating these dry joint problems etc... Ah well. They can't get everything right :zlove:
I would have thought it wiser to send signal from speed sensor to ECU, then the ECU to cluster, but you know those crazy meth-head little japs!
A Big Thank You thanks Lovey very easy job to do .. thanks for the tips m8 ...And a Bigger thanks to My good friend Chilli... with eyes like a hawk he resoldered the complete board..:thumbsup: all back together working like a treat
lucky I did the same and a whole lot more but no change.. gonna have to get a new speedo some day I guess, not much fun if I wanna retain the 300k face.
