96 Q45 power steering and speedometer dead at same time

[espz]

I bought a 96 Q45t with 118,000 miles, and have had this totally random-seeming problem happen to me. The power steering feels dead, like I've lost it entirely, and at the SAME time the speedometer doesn't read. When the speedo jumps back on and hits about 30mph (again random speeds, but that's close) the power steering comes back. What the heck? I'm assuming it's an electronic issue, because otherwise everything works flawless. (I have seen the Transmission Malfunction light come on for a few seconds, four times, always in the morning when its cold, in the last few months of ownership, but assume that's a different issue). This doesn't care if it's hot or cold, it just randomly happens. And they seem to always be connected.

I've done the upper links, and the fuel pump thanks to everyone here, and am about to tackle the brake system, but this one has me stumped, and I can't find anything when searching the fourm.

[qship96]

speedometer and power steering recieve a variable voltage signal that is converted to MPH on the speedometer and used to control steering boost-look for faulty speed sensor.

[maxnix]

Isn't there a relay on the PS pump? A search might bring that discussion to light.

All posts by Q45tech are mandatory reading anyway, so might as well start.

Sure beats the newspaper.

[elwesso]

I agree with Qship

There is a solenoid on the PS rack that decreases the amount of PS "help" at high speeds, so if the sensor is going crazy, that can cause the solenoid to activate and cause it to be as if its going fast...

For the transmission malfunciton, check your codes... Take it to autozone and have them scan it.....

[Q451990]

Not sure if AutoZone can check transmission self diagnostics. Use the method in the service manual.

The vehicle speed sensor is probably the problem? It reads the car and sends it to the ECU for the speedometer and other dependent systems... again check FSM starting on page EC211 .

Heath

[espz]

I ran the diagnostics and the only thing it comes up with is a bad knock sensor. The speed sensor does seem to make sense as the culprit. I have to give Joe a call for brake parts, so I might as well add that into the mix.

You guys rock!

[Q451990]

I'm not sure if the ECU will hold the code with an intermitant problem...

Heath