Yet another 4WS thread

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Mon Jun 11, 2018 5:12 pm

Might be worth just swapping the rear rack by the sounds of it.
They're not a common failure point at all, so a used one should be fine.

Anzezaf · Post by **Anzezaf** » Wed Jun 13, 2018 7:18 am

Im struggling to wrap my head around this. I can reset 4WS errors normally, and I can even make the electronic neutral adjustments without a single problem. I have the sensor aligned within a few milimeters on the steering wheel, as per the manual, everything checks out 100%

But every time i drive more than 10 meters straight, or when i return the steering wheel from max turn back to the middle, I get the 4ws error. It-s always code 28 - main steering sensor Z phase incorrect. This Z phase is basically 5 volts when the steering wheel is in the straight / middle position, and ) volts the rest of the time i think.. So the system is telling me it is not getting those 5V when it expects them when i return the steering wheel to the straight position.

The thing that is troubling me that, when I reset the 4ws errors, I have to turn my steering wheel 90 degrees instead of the usual 45-65 like written in the paperclip procedure. If I dont turn it 90 degrees, then it does not go into error clearing mode and just flashes the error code. Could my steering wheel be mounted the wrong way / offset on the spline shaft?

I also hear a clunking sound coming from the footwell direction when I have the engine off and I turn the steering wheel, the mechanic said that it's play in the steering gearbox in the front?? I have no idea what he meant by that, I will ask him soon. He also said this play could be the root of my problems, and that he had such cases before me.

I'm starting to think that I will start swapping things - 4ws ecu, rear actuator.. this is starting to get on my nerves

Scott560 · Post by **Scott560** » Wed Jun 13, 2018 8:06 am

i have a spare 4ws ecu i can send you if you cover postage (don't want anything for it otherwise), it came form the same car as the sensor where the 4ws was working fine.

There was another thread on here recently regarding resetting the 4ws and that the neutral couldn't be correctly calibrated until the car was physically aligned first.

Having to turn the wheel twice the amount is an interesting problem though - i only ever had to turn 45degrees max. Perhaps the ECU is unable to pick up one of the quadrature channels? i suspect that would through its own code though?

the clonking will just be the track rod end ball joints (inner or outer) shouldn't make any difference to this procedure as they aren't monitored by anything the ECU could determine.

Anzezaf · Post by **Anzezaf** » Wed Jun 13, 2018 10:16 am

Cheers Scott!

We can certainly arrange something for the ECU.
About the clunking, it can't be the outer tie rods as I had them replaced a month ago. As for the inner ones, im at a loss..

However, if there is play in that gearbox the mechanic mentioned, this could be the problem, as it would cause an offset between the main sensor and the sub sensor that's on the rack.

I will try to find out if my steering wheel isn't mounted in the middle / correctly on the spline shaft.
(When i do the electric neutral calibration, I have to turn the steering wheel a wee bit further to one side than the other, a difference of about a centimeter or two)

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Jun 13, 2018 11:38 am

Anzezaf wrote: However, if there is play in that gearbox the mechanic mentioned, this could be the problem, as it would cause an offset between the main sensor and the sub sensor that's on the rack.

That is a valid point - yes.
Play in the track rods (inner tie rod/outer track rod end) would have no effect on that.
Not heard of a prelude steering rack wearing internally before, so you'd be very unlucky if that is the case...

Anzezaf · Post by **Anzezaf** » Wed Jun 13, 2018 6:52 pm

Steering wheel is straight / equal turn angle in both right and left

I think it's most likely the 45 degree offset, that's causing the problem but I do not know where it's coming from...
When the 4ws error pops up, it comes up around that position where the steering wheel is at 45 degrees from the straight driving position.

... Maybe the offset is in the rear actuator. If the rear rack itself is 45 degrees out of center, and the tie rods were adjusted to go straight (when the rack was frozen in the error position) by the previous owners...

Post by **Vtecmec** » Wed Jun 13, 2018 7:07 pm

I'm sure I've said it before, but have you checked each sensor is centred via the electronic neutral check?

Post by **Vtecmec** » Wed Jun 13, 2018 7:10 pm

Anzezaf wrote: ... Maybe the offset is in the rear actuator. If the rear rack itself is 45 degrees out of center, and the tie rods were adjusted to go straight (when the rack was frozen in the error position) by the previous owners..

If the rear wheels point straight when the error code is in effect,, then it is lined up properly as the system locks the rear wheels at centre when there is an issue.

Anzezaf · Post by **Anzezaf** » Fri Jul 06, 2018 8:08 pm

This was a triumph.
I'm making a note here: HUGE SUCCESS.

IT'S FINALLY WORKING !!

I switched the 4WS ECU with a new one that @Scott560 supplied free of charge (again, cheers for this guy, he's top fella).
Switching the ECU itself however wasn't the whole solution, I also had to make a front sensor neutral adjustment and after that it looks like it's working. Drove about 3 miles with the biggest smile on my face

. Then went to a nearby parking spot and just spinned around a street light post like i was gone in the head haha.

Damn, im happier than a kid on christmas

And the car itself is really spectacularly different, it feels like you're driving a shopping cart rather than a longer-than-monday car

Post by **Vtecmec** » Fri Jul 06, 2018 11:17 pm