5th gen rear upper wishbones on 4th gen with 4ws

[vanzep]

Just wondering if anyone else has fitted 5th gen reinforced rear upper wishbones onto 4th gen with 4ws?

The 5th gen ones are twice the weight due to having the reinforcing plate welded to them - wondering if this could be the cause for the 4ws motor power unit fault code (and notchy feeling from cold). Thats why im asking if anyone has used then on 4th gen with 4ws

[Merlin]

I don't think that will be a factor, all the upper arms do is allow the knuckle to twist (for 4ws cars), and to move up and down as the coilover compresses.

I was reading the 4G service manual, and I wonder if it is an issue with the voltage regulator for the motor. If the motor gets too much voltage, it will turn itself off. Maybe that correlates to you only hearing one click from the 4WS ECU/relay. I'll have a look again later and see if I can find it.

[vanzep]

Thanks Merlin - thought it worth asking about 5th gen upper wishbones as fault seemed to coincide with me fitting them on the 4th gen.

[Drax]

could the 4ws be out of allignment since they were fitted? maybe use a 4ws locking tool to get the wheels laser aligned, then do a 4ws reset...

[Merlin]

Vanzep shared a vid with me that showed the 4WS code being 62, which affects ABS control unit (Vanzep, that is probably why you are also getting an ABS fault code), Rear actuator motor, and Power system harness (as described in section 17-41, page 687)

In section 17-71 of the 4G service manual, it shows the diagnostic flow to resolve codes 60,61,62 and 63. Basically, you have to test the 4WS control unit power terminal.

[wurlycorner]

Ref that flow chart above, I suggest an extra test also - if there's 12v from the A terminal white to ground, that only proves there's voltage, doesn't prove there's good current carrying ability on the circuit (and that is needed for it to actually work).
To test the latter, connect a high current bulb (e.g. a headlight) between the A terminal and ground. If it lights up bright, you're all good. If it's dim, then you have high resistance somewhere in that wire (corroded terminal/chaffed/corroded wire etc.) somewhere from the battery to the ECU.
(You could also then do the same test at the relevant terminal on the rack motor itself, when power is being supplied to it)

[vanzep]

Thanks for the input guys - much appreciated - electrical stuff is not my bag.
The tcs code I was getting could be related to ABS but i would not be aware as the new dials i recently fitted dont have abs light
Maybe I should refit the old dials so i can see the abs fault code. Ive also got spare 4ws, abs & tcs ecu, loads of relays and fuses - normally i would just start replacing ecu's in an attempt to resolve things.
Maybe a more scientific approach is needed

[wurlycorner]

Definitely need to get the ABS code!

[vanzep]

Thanks Wurly - ive looked out the old dials with abs indicator and found all 3 ecus (4ws/abs/tcs)

[Scott560]

If you have voltage at the connectors for the ECU, but are still getting the power error codes, it's most likely the solder joints.

As Ian says, a weak link (high resistance) in the wire could be confirmed with a decent current (high wattage bulb) , but it won't pinpoint if the problem is further past the multi plug, eg, inside the ECU where the mulitplug connector meets the PCB.

I'd reflow the solder joints before doing any other kind of diagnosis. The computer can only really tell you what is up if it is working properly, and it can't do that if the solder joints are cracked, which is a known issue.