Does anyone know what frequency the Power Steering solenoid is being driven from the PS controller. I'm trying to replicate speed sensitive steering using a Haletch ECU to PWM the PS solenoid. I can find the voltages in the manual but there doesn't seem to be any reference to the frequency the solenoid is switched at. Unfortunately I don't have a stock setup to measure. I can achieve the correct voltages measured at the solenoid and have tried frequencies from 50 - 1000hz. Low frequencies makes the solenoid buzz like crazy. Has anyone played with this? I assume there will be others who will be using an after market ECU, so what have you guys used? Thanks
Oops, Typo in thread title. Should read Power Steering Solenoid switching freqency. For those who might be interested. Done some more testing / experimentation on this. Now Running frequency = 20Hz, PWM using a 2D table, VSS @ 20Km steps versus duty cycle. Max assist 100% @ 0Kmph ~ battery voltage 80% duty cycle @ 20kmph ~ 6.8V at solenoid steps to 40% @ 100Kmph ~ 2.6V at the solenoid.
Hi Ivan, I can't answer your question but I do remember finding some great information from Garry Stotts/DVDBurn on twinturbo.net that may or may not have what you're after...
Thanks for the reply. I'm pretty close to having it sorted now. Just a few more drives and tweaks to the duty cycle table to achieve the road feedback feel that I'm comfortable with and I'll leave it. A google search turns up a frequency of 123Hz however this must be wrong because the solenoid buzzes like crazy at this frequency. Experimenting with the frequency using variuos duty cycle values, I found that 20Hz seemed to make me comfortable with the sound from the solenoid and voltage readings. And rather than aiming for the OEM voltages, (0Kmph = 4.4 - 6.6V & 100Kmph = 1.8 - 2.8V) I've used duty cycles that give the assist and road feel that I like. So my OP table now uses different duty cycle value to the above. I have heard of guys just disconnecting power to the solenoid however the steering becomes too heavy and other guys who claim to just apply battery voltage to the solenoid but this then makes the steering too light at speed. Variable assist is the go. I'd be interested to hear from anyone else using an after market ECU to control their power assisted power steering.
