Steering Position Sensor Pinout

[pretzil]

Hi guys.

After having a belt driven pump fail on a skid pan day, as it seems is not uncommon, I am looking into fitting up an electric power steering pump - really just to see if I can...
I would like to have it come on when the steering wheel is turned (among other conditions).

Can anyone help me with a pinout for the Mitsubishi steering position sensor and maybe a description of the voltage signals it outputs.

I am hoping there is an encoder in the column that outputs a voltage ranging from 0 to 5Volts and I can use it to trigger a voltage switch.

Thanks.

 

[Tony_T]

Don't know for sure but industrial encoders output two pulse trains spaced about 90 degrees apart so that logic circuitry can determine offset and direction. I'd assume the steering encoder will be of this type also. It may have a third output which is an index of only a single pulse per rotation to give a centre position indication. It won't be a linear voltage output so a voltage comparator will not do what you want: you'd have to count pulses from the centre. Levels will most likely be 5 volt.

 

[pretzil]

Found the sensor. Has about 80 notches on a metal disc

 

[pretzil]

So this is what it looks like, 2 wires pulse on and off 3 volts as it passes over the notches.
1 Wire reads 2.7volts at all times unless the long notch is bottom dead center. Unfortunately this happens both when driving straight and again at around 75% lock in each direction.
I suppose the ECU is smart enough to work out which is which.

In case anyone is looking for this for any reason in the future, lets give the 'search' function a helping hand with some tags so people at least have a fighting chance:
steer steers steering position sensors SPS notch notched notchabusiness disc disk discs disks column elect electric electronic pin out pinout


NOTE: I inspected this wiring with the alternator belt removed, actual voltages may be higher in practice.

 

[smohekey]

Which wire is which?

Looking at the placement of of the long notch in relation to the few short ones next to it, the ecu will be able to determine whether your leaving center from the left or the right (due to each end of the long notch being either over a short notch or not), but after that I can't see how it would know the difference between doing (for example), half a turn in that direction, or simply tuning it back and forwards over a single small notch for half a turns worth of notches.

As far as knowing whether the long notch represents center, or 75% either side of that, I imagine it would assume the first one it sees is center, and from there correct if it sees two long not entries after it leaves the initial long notch.

 

[pretzil]

I would assume the same, it would correct itself, ecus are pretty smart.

I should have marked it down, but I think the dead centre wire was the wire on its own row.
Noting the plug looks like this:
________
O O O O
O
------------

 

[smohekey]

Im wondering now whether the sensor at the bottom is actually two sensors for the outside, smaller notches, while the sensor on the right is for the larger notch. If that were the case, the ecu could detect the direction of motion by the sequence in which the bottom two sensors see notches.

 

[naughtika]

thought the sensor is only on the bottom.. as I did pull apart 1 set. the black prortruding part is part of the iindicator stalk where it is pushed out when indicator (L or R) is used

 

[pretzil]

Im wondering now whether the sensor at the bottom is actually two sensors for the outside, smaller notches, while the sensor on the right is for the larger notch.

I think the piece you are calling the sensor on the right (at 3 oclock) is the piece that clicks the indicator off as you turn, its just a piece of plastic and interlocks with the 3 white 1/3rd pieces.

 

[smohekey]

Got it. So is it at all possible there are three sensors in the bottom part then? I.e. one for the long notch, and two for the small ones?

 

[pretzil]

Hey, do these loggers read steering position sensor values?

Evosvan does

Hey Steve,

What kind of values does evoscan show? Is the reading on a graduated scale? Does it have left and right?

I've heard that there is a way to customise an output wire from the ECU to give a signal under certain conditions - Would there be a way to get an output when the steering wheel is turned maybe 20% or something?

 

[pretzil]

I know I am over-complicating this, but humor my ambition.

 

[smohekey]

I'm more interested in knowing how the sensor itself works, as I'm using a Link G4+ Extreme.

 

[TME_Steve]

Hey Steve,

What kind of values does evoscan show? Is the reading on a graduated scale? Does it have left and right?

I've heard that there is a way to customise an output wire from the ECU to give a signal under certain conditions - Would there be a way to get an output when the steering wheel is turned maybe 20% or something?

It displays it as degrees but you could probably query the ayc module and output something. @BCX the ecu wouldn't know would it?

 

[BCX]

Yeah, ecu doesn't read in steering wheel sensor. That's a TCL/ayc/trace control function.

Need to log ayc or TCL. For that output. The output after it is scaled is in degrees. + for right, - for left but I haven't played with it. ayc for me is one more thing to leak/break. So opted for a typev

In terms of what your trying to do... Seems like it's a optical encoder wheel. You could feed this output into a microcontroller like an atmel. Also seems there is a 0 degrees mark so could even do that. I'd say there is a dedicated output for that.

Will check some wiring diagrams I have for a magna/verada with trace control to see the pinout.

 

[smohekey]

Sorry, was using ECU in the generic computer thing sense.

Thanks Bill.

 

[BCX]

1 Wire reads 2.7volts.

this would be about right. At a guess, the would sensor be an open collector input, and earths out to ground. The power for this signal line is provided by the computer.

This is very common with a lot of sensors... speedo is another example of this. And also the Continental flex sensor that i'm working with for flex.