Hello alll,

Santa`s clearly been a naughty boy and the spirit of christmas zeds has decided to take away his power steering.

It`s been displaying symptoms for awhile, mainly being a little stiff first thing (steady now) but being ok when warmer.

The hicas light came on the other night along with a drop in assistance.

I did the usual and checked the levels. Seems ok but my float is worn and it`s always a guess. So i used a probe and measured this against the guage. All good. Still the same result so It`s not that.

So, as i drive off all is good then after 10-20 secs or over say 15mph the steering gets heavier but not totally gone, then shortly after that the hicas light to bring my attention to a fault. Looking at the manual it states that this occurs if the ecu is not getting a signal relevant to the cars speed so goes into a failsafe sort of mode and stops the hicas. This also keeps the steering at motorway speed assistance levels.

The temperature thing makes me think it`s an electrical connection issue. I`m aware the signal path comes from the gearbox thru the speedo head to the hicas ecu and then that gives the relevant signal to the solenoid etc. Now my speedo reads fine (but it could be the pass thru connection on the board). That rules out the gearbox speed sensor. Next is this pass thru connection. Does anybody know which wire it is?

The fact that the steering still has some form of assistance and points in this direction but it`s hard to find any information on which components or sensors cause which symptoms apart from that which i`ve already stated.

Anybody?

Is your steering wheel on straight?

 

Driving for a while at a decent speed in a straight line with the wheel thinking you are turning will bring on the hicas light

That side of things is fine mate.

Does your speedo also stop working?

Maybe a problem with the hicas steering boss? I've heard that that can throw up problems with the PS. Just a guess though :)

Check the sensor on the steering rack, may be a cruddy pin on the sensor plug, is the steering bled properly, turn the wheel far right then far left with the cap off the reservoir to see if the level changes.

Check the sensor on the steering rack, may be a cruddy pin on the sensor plug, is the steering bled properly, turn the wheel far right then far left with the cap off the reservoir to see if the level changes.

pressure sensor or solenoid?

Also the pass thru point as far as i can surmise from circuit diagrams and a bit of common would appear to be the 2p part of the speedo head. If 2p stands for secondary power or even, to power (steering ecu) than that would make sense.

Does cruise control work ?

 

if not, the problem is most likely your speedo unit...it doesn't output the pulse signal (2P) that is needed/used by several ECU's to determine vehicle-speed

Hi lymon, I've literally just finished going over the speedo board with a soldering iron. I haven't checked the cruise control yet. My thoughts are exactly that though. The speedo isn't putting the signal out. I noticed some questionable joints on some resistors and the main chip, so I've attempted to solder both sides of the board in these areas. The speedo stopped working earlier in the year due to a bad joint on a capacitor. Looks like age is catching up with the boards. Already had to fix the fuel ecu due to the same issues.

Just took the car for a spin around the block after refitting the resoldered speedo head and cleaned and retensioned connectors. Power steering is back. Fingers crossed it`s permanent, but what a difference.

Bugger..not permanent. Just taken out for spin. Checked the cruise control as lymon suggested and no it wasn`t working. Every now and then the set light would try to engage. As before, the hicas light came on, steering went a bit stiff until the car warmed up then all came back on line. Cruise working ,steering normal but the hicas light remained. Definitely electrical. and bloody frustrating!

ok, so i resoldered the steering ecu but still nothing. Hicas light is on and no power steering at all even sitting at a standstill whereas before it was intermittant. I noticed one of the diodes? looks burnt. Would a bad neutral switch bring this fault on? Or even the steering pot sensor as mines crap and i can never get a reading.

Edited February 17, 201510 yr by santa

this the suspect D10

just a though, have you tried the speed sensor on the gearbox? Common problem to cause heavy steering, light on etc. Ive had 2 go on me now. Its underneath. only a 10mm bolt and it comes out. just a thought bud

i have thought about it. did your speedo still read correctly as that side of mine is fine.

Update..twas the hicas ecu. Something had failed in one of the components.

Luckily for me Mr Feeney had just the very thing lurking in a dark corner. Issue resolved.

Update..twas the hicas ecu. Something had failed in one of the components.

Luckily for me Mr Feeney had just the very thing lurking in a dark corner. Issue resolved.

 

Nice one! Glad you've got to the cause of the issue and thanks for completing the thread as it may help others in the future with a similar issue.