R32 Lost power steering

[J.sutton]

Hi team

So my R32 has a lock bar in the rear, and recently changed out the power steering pump for a non hicas one.

At first my steering was mildly heavier but still workable. After a short period (hours) i seem to have lost all power steering... 🙃

 

Any ideas what to start looking for?

[GTSBoy]

The HICAS CU controls power steering. It might be unhappy with you disconnecting HICAS solenoids. If that's the case, it's not insurmountable. I have completely removed all HICAS hardware from my car except the CU. Many years prior to that, because of a steering sensor fault, I just disconnected the smaller of the two plugs on the CU. That prevented the steering sensor fault from putting the HICAS into lockout (which wasn't a good place to be, trust me!) and kept the light off the dash. The HICAS CU still appears to be happy with the situation many years since removing the rest of the hardware. So I suggest you try disconnecting that plug first.

But there are other ways that the power steering can die. I once had my oxygen sensor die with a short in the power wire that runs its heating element. That power wire runs in the same loom next to the wire running down to the steering rack, and that wire got damaged by the loom short and I lost assistance. Dead heavy. Real hard to find the problem, but an easy fix once found. I'm sure there are other secret squirrel ways it can die.

You would be advised to start at the assistance solenoid on the rack and see what voltage is present, work backwards from there.

 

[alexj]

Zero power assistance is stupidly heavy and would need to be mechanical failure; belt off or no fluid in the system. I would guess you are not quite there and just have "very heavy" steering?

As above, i would start by checking the power steering solenoid is getting its signal from the hicas brain. It is a pwm signal and you can probe it on a dedicated pin on the consult port - a bit more convenient than back probing the connector on the rack. If you have a scope you can see the pwm duty or just use dvm to measure the voltage. The workshop manual has a diagnostic procedure for this. Its a few years ago but from memory 30% duty or 4v is what you are looking for.

[sedanboy]

On 4/15/2021 at 10:23 PM, J.sutton said:

Hi team

So my R32 has a lock bar in the rear, and recently changed out the power steering pump for a non hicas one.

At first my steering was mildly heavier but still workable. After a short period (hours) i seem to have lost all power steering... 🙃

 

Any ideas what to start looking for?

bruv dealing with a similar issue at a drift event ive had my 02 sensor fall onto my turbo and practically melt the thing into macaroni what exactly did you do to solve the issue of the burnt up wire for the rack ? my steering is dead heavy almost nonexistent 

[sedanboy]

On 4/16/2021 at 12:02 AM, GTSBoy said:

The HICAS CU controls power steering. It might be unhappy with you disconnecting HICAS solenoids. If that's the case, it's not insurmountable. I have completely removed all HICAS hardware from my car except the CU. Many years prior to that, because of a steering sensor fault, I just disconnected the smaller of the two plugs on the CU. That prevented the steering sensor fault from putting the HICAS into lockout (which wasn't a good place to be, trust me!) and kept the light off the dash. The HICAS CU still appears to be happy with the situation many years since removing the rest of the hardware. So I suggest you try disconnecting that plug first.

But there are other ways that the power steering can die. I once had my oxygen sensor die with a short in the power wire that runs its heating element. That power wire runs in the same loom next to the wire running down to the steering rack, and that wire got damaged by the loom short and I lost assistance. Dead heavy. Real hard to find the problem, but an easy fix once found. I'm sure there are other secret squirrel ways it can die.

You would be advised to start at the assistance solenoid on the rack and see what voltage is present, work backwards from there.

 

bruv dealing with a similar issue at a drift event ive had my 02 sensor fall onto my turbo and practically melt the thing into macaroni what exactly did you do to solve the issue of the burnt up wire for the rack ? my steering is dead heavy almost nonexistent 

please forgive the double quote its my first time posting here any input is hugley appreciated

[GTSBoy]

Copy-paste of reply to PM.

The loom that contains the power wire for the O2 sensor also carries the PS wiring and when the power wire melted and burnt, it took out a couple of other wires in that loom, including the PS wiring. So, I just repaired the broken wires. Had to split the loom open and do a bit of surgery on a few wires.