R32 GTR Power Steer issue

[Dorifudo]

Hi All,

I have recently changed my dash to one of Link's new digital dashes, managed to get the speedo and odometer working by using the S13 speedo sensor as they run a analog to digital converter and sends the signal to the ecu then onto the dash. My problem now though is that i feel like i have no power steer at low speeds, which i am guessing with the factory setup the speedo drive cable goes to the dash then from there sends a signal to the hicas pump( i have removed hicas) 

Unfortunately my mechanic isnt really too familiar with it so we are a bit stuck. Any ideas? im guessing in theory i need to get the speed signal to the hicas ecu?

 

Regards

Jeff

[Duncan]

Really interesting how different people feel the power steering impact. I haven't had speed input in my 32 GTR for years and am happy with the weight. Yes it is heavier than a modern car but not unmanageable.

Sorry I can't help with the 33 GTR wiring, I've only ever seen manuals in japanese not english

[GTSBoy]

If the ECU is getting a speed signal then the HICAS CU is getting it. They're all on the same bus. (So long as you haven't damaged the appropriate wiring, that is).

The signal goes nowhere near the "pump". There is a solenoid valve on the front rack. That is PWM controlled by the HICAS CU to provide assistance from hydraulic pressure. It could be stuffed. Check for voltage there and see if it is still even receiving power. If it is not, then the power feed wiring could be at fault. I burnt that wire when my oxy sensor had a severe problem and damaged a couple of wires (they run in the same loom).

[Dorifudo]

On 10/12/2020 at 1:09 AM, GTSBoy said:

If the ECU is getting a speed signal then the HICAS CU is getting it. They're all on the same bus. (So long as you haven't damaged the appropriate wiring, that is).

The signal goes nowhere near the "pump". There is a solenoid valve on the front rack. That is PWM controlled by the HICAS CU to provide assistance from hydraulic pressure. It could be stuffed. Check for voltage there and see if it is still even receiving power. If it is not, then the power feed wiring could be at fault. I burnt that wire when my oxy sensor had a severe problem and damaged a couple of wires (they run in the same loom).

Something weird has happend, when infirst start the car, i would have powersteering for about 3kms then steering would get heavy and stay like that until i start the car again.

[GTSBoy]

HICAS CU could be going into fault after that time.

[BK]

1 hour ago, Dorifudo said:

Something weird has happend, when infirst start the car, i would have powersteering for about 3kms then steering would get heavy and stay like that until i start the car again.

That's because the HICAS computer waits for a predetermined period of time to receive a speed signal and confirm all other sensors. If it doesn't get all correct signals, it kills all power steering assistance. It really does appear that your speed signal is not correct at the HICAS unit.

You really need to go into HICAS diagnostic mode and check the fault codes from the unit. I'm not sure how you're going to do that without the HICAS dash indicator to flash codes, which I guess you don't have with your new Link dash.

If you do have a HICAS indicator, there are tutorials on how to enter it and read the fault codes on SAU.

[GTSBoy]

16 hours ago, BK said:

I'm not sure how you're going to do that without the HICAS dash indicator to flash codes

The way is the way that I have always preached. Go to workshop with a proper scan tool. Takes 5s to hook up and read out.

[BK]

Agree it mght be the only way to go to diagnose the HICAS now. That said, I don't know where Jeff lives in NZ but getting access to a proper scan tool might not be so easy for him. We all don't live in a major city.

I know if I needed one here I'd have to go 1500km down to Adelaide to find a workshop with one, because I know the only ones around here would be factory dealerships who no way would connect to any import.

[GTSBoy]

That's sad. Any decent private workshop down here has at least one good scan tool.

[BK]

I know.

I need to move.