Speed Sensitive steering and R154 speed sensor questions

**Bowlsclubboy** · 22-10-2007, 08:05 PM

Hey guys, thanks to you lot my adaptronic has been working fine for a few months.

I've finally gotten around to pulling the loom out of the car to finish it off (conduit etc)

Currently my speed sensitive steering solenoid on the rack (JZX81 Type) is on a PCM output and is handled as a stepper motor. I simply have this set so that it goes to full soft (full open stepper motor) once water temp gets up to 60deg, this way i can 'feel' when the car is warm lol..

My question is; Can I wire this as a 'low current' regular +12 output so as to free up a PCM output? Or would i do damage to the motor by having it held open with constant 12v...i am unsure as to how stepper motors work in fact.

1jzracing said he did this to the hydro fan setup when he used it as a power steer pump but im not sure if the solenoids work the same, nor do i know if the 'low current outputs' will have enough juice to do the job.

Last question is thus: Upon just realising that i had in fact wired my reverse light switch as my MVSS (this would explain why it doesnt work!!!)
The REAL Speed sensor has 3 wires, red, white and black...i would imagine the white one would be signal wire and i read elsewhere that the other 2 should be ground?

Cheers,

Troy

**wilbo666** · 22-10-2007, 08:55 PM

Originally Posted by Bowlsclubboy

Last question is thus: Upon just realising that i had in fact wired my reverse light switch as my MVSS (this would explain why it doesnt work!!!)
The REAL Speed sensor has 3 wires, red, white and black...i would imagine the white one would be signal wire and i read elsewhere that the other 2 should be ground?

Cheers,

Troy

MVSS = speed sensor?

For the speed sensor my suggestion is:
Red = +12V Pwr (Via Gauge fuse?)
White = Speed sensor signal
Black = Ground

Cheers
Wilbo

**Bowlsclubboy** · 22-10-2007, 09:01 PM

Yep, MVSS = Master Vehicle Speed Sensor, at least that's what the Adaptronic manual says!

Thanks Wilbo, you're a champ.

**mrshin** · 22-10-2007, 10:53 PM

Does your ECU have a speed sensor input, that would could control a PWM output? If the ECU output can't handle the current, use an external transistor.

**ra65** · 23-10-2007, 12:39 AM

Extract from megamanual about idle stepper motors. If you want to pull it off, would expect it to be much the same in terms of what it does, so this test would probably work.

Then you need to select the 'Idle Control/Algorithm' in MegaTune. In some cases setting the stepper motor to "IAC Stepper Always On" will cause the IAC to get hot. However setting it to "IAC Stepper Moving Only", might cause a problem with idle speed changing from one start to another.

You can test if your IAC is suitable for 'always on' by leaving your stepper powered on the bench for 15 min or so. If it doesn't feel too hot to you, then set it to "Always On". Apparently this is what GM does. But if you want to be safe they should test it on the bench for 15 min or so, or monitor it closely in the car while not moving for at least 15 minutes, checking the IAC temperature frequently with your fingers. It may get warm, but it shouldn't burn your fingers just touching it.

**cptsideways** · 23-10-2007, 04:51 AM

You'll find the steering extremely light with a full 12v, it does however work by supplying it say 6-8v at least I think it does??

On my drift car I have it switchable between 12V & 0V the latter for the track, its very heavy but nicely damped.

**Bowlsclubboy** · 23-10-2007, 06:31 PM

thanks again everyone...if cpt sideways just pumps current straight into it with no apparent dramas, sounds good to me.
Ive been using full 12v for a while now (just maxed out stepper trim) and i'm used to it so i'll go with that.
Cheers,
Troy