Hicas Diagnosis

[GTST R33]

This was to do with a topic i posted earlier where my HICAS light came on after after short trips

and this caused my steering to become heavy (see HICAS LIGHT +HEAVY STEERING)

Ive just run plugged in the standard ECU and run a diagnostic system check

ps:diagnostic computer will not communicate with aftermarket ECU

The readout from HICAS was - 25 Engine Rev abnormal signal

Does anyone know what this means?? Would it be to do with reverse (speed sensor) on speedo/gearbox

The error code i chased up on this site for HICAS diagnostic Codes 1993-1999

and came up with: 25 Rear sub sensor input not present

would this be the smaller of the two sensors to the right of the HICAS motor

i guess the sensor or plug could be faulty??

Anyone had the same problem?? or any suggestions on what i need to do??

Thanks for everyones input!

Edited December 5, 2008 by GTST R33

[PUDZ 32R]

if you had heavy steering it is not a problem with a sensor mate as the power steering is not electronically controlled. only the hicas is but it is fed from the same power steering hydraulic pump. i would be checking the power steering fluid level and check if the fan belt is tight etc before checking computer stuff. if the belt is tight (able to push the side in about 10mm,~6mm with gates racing belts) and there is plenty of fluid your pump might have a shot seal etc... i highly doubt it will be a sensor playing up as i said before.

[heller44]

How do you think the speed sensitive variable assist power steering works then?

Electrical solenoid on the steering rack actuated with a varying pwm signal. Electronically controlled.

[GTST R33]

How do you think the speed sensitive variable assist power steering works then?

Electrical solenoid on the steering rack actuated with a varying pwm signal. Electronically controlled.

I believe it is an electrical problem to do with the signal for the HICAS

after runned a scan i was given the error code above im just not sure what i need to do to fix the problem

would completely removing the HICAS system & added a HICAS lock possibly eliminate the problems im having??

i was hoping someone else may have had the same problem and was able to point me in the right direction

or advise me of somewhere i can take the car in Adelaide to get this sorted??

[heller44]

I don't know enough about the wiring system in the 33 to be a lot of help, I have the complete wiring set for the 32 though and have had to repair quite a lot to get the hicas and power steering working properly on my car. If you can lay your hands on a copy of the 33 schematics that would be great, but I haven't seen any about as of yet.

If the diagnostic threw out engine rev as a fault then i'd be making sure that the engine speed signal was getting to the hicas module. I wouldn't assume that the 25 the diag unit spat out is the same as the 25 listed for the hicas fault, unless you know better..

If you do a diagnostic with the turn steering wheel x times drive forward crap what fault code do you get coming up then?

Removing hicas and locking it out won't fix the steering issue.

[SilverECR33]

if you had heavy steering it is not a problem with a sensor mate as the power steering is not electronically controlled. only the hicas is but it is fed from the same power steering hydraulic pump. i would be checking the power steering fluid level and check if the fan belt is tight etc before checking computer stuff. if the belt is tight (able to push the side in about 10mm,~6mm with gates racing belts) and there is plenty of fluid your pump might have a shot seal etc... i highly doubt it will be a sensor playing up as i said before.

the Hicas is infact 'electronic'......... .. ..

Look I've had the same issue for a while now, we have confirmed, all power steering mechanical and hydrolic elements are working properly. The issue is intermittent like yours aswell, (light on + steering heavy), and it also does it now and then.

I have been searching these forums for my old thread, but have been unable to find it.

Ive made numerous phone calls, spoken to all types of work shops, on this matter. Including a fair few suspension specialists. and No one has any idea of the cause, and no one has nessesary tools or equipment to diagnose hicas issues. Our only hope may be in Japan.

If you find anyone in australia who does please let me know. As I would like to keep my hicas working.

[heller44]

If the light comes on, there will be a fault listed. What do you have coming up when you do the hicas diagnostic? These cars might seem it at first glance, but they aren't all that complicated.. Just need to know the right way to approach the problem.

I've managed to get my power steering, hicas, and 4wd all working again when the monkeys that had the car previously were masters of the twitch and tape method of installing.. with wrong wires..

At one point I had nutted out the waveforms for the solenoid control and was going to build a module to do the conversion from speed to power steering solenoid driver but worked out how to fix mine before I had gotten that far.. would be the ideal solution for those that want to remove and lock out hicas but still have good power steering.

Edited December 8, 2008 by heller44

[GTST R33]

Currently i have someone looking at my HICAS & hope to narrow the problem with more diagnostic checks

the power steering pump and hoses/fluid have been checked and im quiet sure its an electrical fault, for some reason the signal from the speed sensor isnt giving the correct signal, the angle sensors have been checked and seem to be in working order, once the light is off i can start the car as many times as i like and the light will stay off & its only after i move the car and then restart then the light comes on. Its becoming very frustrating as i dont know of any experts in this field and im believe the problem could be fixed easily using a process of elimination to find a fault. Im going to clean all the contacts thoroughly to see if a poor contact could be to blame.

If anyone has had or fixed this problem or has any input it would be greatly appreaciated

[Stitch]

Currently i have someone looking at my HICAS & hope to narrow the problem with more diagnostic checks

Can you keep me in the loop and tell me what they find, I have the same problem. It's extremely frustrating!

Thanks!

- Ben