Jump to content
SAU Community

Using Haltech Pnp Platinum To Control Power Steering Solenoid

HarrisRacing
 Share

Recommended Posts

HarrisRacing Proficient

HarrisRacing

Posted
Posted

I understand from previous replies that the power steering solenoid on the rack acts in such a way as follows:

1) At no voltage applied a plunger is retracted via internal spring and this opens a port that releases pressure from the input of the rack to make steering feel heavy (bleeds off pressure supply). I confirmed this on mine.

2) When applying voltage It worked the plunger at as little as a 9V battery and polarity was not a factor (swapping poles made no difference to operation). I did NOT try lower voltages (sorry). When this is energized, the bleed hole is plugged off and all pressure goes through the rack for very light steering feel.

3) The HICAS computer sends a squar(ish) 123 Hz wave of varying voltages to this solenoid under different modes of operation (found in another thread here). This is basically changing duty cycle of the wave depending on vehicle speed.

at 0 km/hr the solenoid sends roughly 4.4-6V which is approximately 32-47% duty cycle (at 14V).

at 100 km/hr the solenoid sends roughly 1.5-2.2V which is approximately 11-16% duty cycle (at 14V).

4) When removing Hicas parts (or if something in the system is bad) the HICAS computer may disable this function (de-energize the solenoid) and leave the solenoid in constant bleed state (see #1 above).

Here's my plan:

Use a spare Digital Pulsed Output (DPO) from my Haltech PnP Platinum pro (R32) to control the output based on speed of the vehicle. I will need a digital relay for this and use one output from the aux harness.

I added a DPO as an output and called it "Generic Duty Cycle Output" set at 123 HZ in the software and then made a table with 0-200 mph (yes mine is set to mph), and used 50% duty cycle for 0 mph and 0% for 70mph and up and then just linearized the table in between these values. This way I am going to run high duty on low speeds and linearly decrease duty until hitting 0% steering assist at all speeds over 70mph (so when I'm cruising on the highway my solenoid gets a break totally).

Has ANYONE tried this before? I'm going to be getting my car running soon and am currently setting up the Haltech wiring and I/O's. I just wanted to see if anyone has tried this yet.

Thank you,

Patrick

  • Like 1
dontfeelcold Experienced

dontfeelcold

Posted
Posted

I haven't tried it. What you are doing should work.

The best place to start would be to use an oscilloscope to measure what the solenoid sees (from the factory HICAS ecu) and log it then replicate that in the haltech.

  • 3 weeks later...
HarrisRacing Proficient

HarrisRacing

Posted
  • Author
Posted

After getting the car done the steering doesn't feel bad at all. Probably not worth changing tbh. I'll save the pulsed output for something more useful (like fans, etc).

  • Like 1
  • 4 weeks later...
Sub Boy32 Rising Star

Sub Boy32

Posted
Posted

Mine is running through my Link G4+

Being that I have removed the factory dash and replaced it with a IQ3 Digital Dash, it no longer sends the signal to the ECU to control the speed sense valve on the power steering.

I'm not entirely sure what I/O my tuner has connected it to, but it works just like it used to with the factory dash.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • soviet_merlin
      Duncan's V37.......race car?

      By soviet_merlin · Posted

      Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
    • Murray_Calavera
      Jacks that fit under GTR lips that can reach the subframe?

      By Murray_Calavera · Posted

      My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Duncan
      Chris' Toyota Mark ii JZX110

      By Duncan · Posted

      Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
    • Duncan
      Jacks that fit under GTR lips that can reach the subframe?

      By Duncan · Posted

      BTW I measured the jack I have, it is 70mm at the saddle but you only have about 700 until it returns to 150mm high at the cylinder so it is good but no magic bullet.
×
×
  • Create New...