Wiring diagram - advice please (photos)

[SKS Disco]

Originally Posted by Jamiewelch

Just so you know, the codes are below (with checksums)

713601117
218048C18108024A3
0400000041K

As Brian has said, V6 cruise works without coding, you just can't run diagnostics on it.

Cruise is enabled with those codes anyway.
Number 8 colour in red.

So I'm out

[SD1too]

This is what I would do next Dougie. I'd break your new connection from the interface ECU C0895-9 to the cruise ECU C0239-1. I'd then supply C0239-1 directly with +12v to see if the cruise ECU will then reward me for providing it with a power supply.

What do you think?

Simon

[goltho]

Originally Posted by SD1too

This is what I would do next Dougie. I'd break your new connection from the interface ECU C0895-9 to the cruise ECU C0239-1. I'd then supply C0239-1 directly with +12v to see if the cruise ECU will then reward me for providing it with a power supply.

What do you think?

I'll tell you what I think Simon. I think if I was 40 years younger, I'd marry you & have your babies.

It only bl00dy works!! Engages and disengages when it should (road speed, gears, brakes), the IPK light is fine, and because I mounted the vacuum pump on the right-side bulkhead, I can hear it BRRRP when it does its thing (I thought it was the ABS to start with & panicked a little )

So I guess the cruise relay needs to be condemned after all? If so, no big shakes there.

I really could not have done it without your reasoned input and systematic diagnosing, Simon. It's been a complete bu99er but also a really good learning experience. I'm glad in the end that my wiring was fine, although I would've been equally glad to admit errors to solve the problem. I'm a great believer in paying things forward, so maybe I'll be able to advise some poor bloke struggling with his KV6 cruise retrofit, to not bother.

Dougie.

[SD1too]

Originally Posted by goltho

I'll tell you what I think Simon. I think if I was 40 years younger, I'd marry you & have your babies.

You've got a great sense of humour Dougie!

Originally Posted by goltho

So I guess the cruise relay need to be condemned after all?

Well it's a bit odd. From where did you get the cruise "relay"?
Edit: Surely the absence of the Shift Interlock ECU couldn't be responsible?

Originally Posted by goltho

I really could not have done it without your reasoned input and systematic diagnosing, Simon.

Thank you very much Dougie. Not everyone judges my methods that way. You're a gentleman.

Simon

[goltho]

Originally Posted by SD1too

You've got a great sense of humour Dougie!

Just as well, eh?

Originally Posted by SD1too

Well it's a bit odd. From where did you get the cruise "relay"?

eBay, as part of a "retrofit kit" (pump, throttle body & actuator, ECU, interface, paddle switches, master switch and - oddly - an EAT module which I didn't need). They were all quite tatty & showing signs of lying around in a damp environment.

There's one on eBay about 30 minutes from me for around a tenner so I'll have it and see how it performs. I now need to stop myself thinking ahead ("What happens if that doesn't work.."), although just because I'm paranoid doesn't mean my cruise control isn't jinxed....

Dougie.

[goltho]

I just spotted your edit about the shift interlock. I was wrong about that - it is there although it doesn't require the brake switch's input.

What harm might be done to leave it wired the way I did it today as the workaround?

Dougie.

[SD1too]

Originally Posted by goltho

I just spotted your edit about the shift interlock ... it is there although it doesn't require the brake switch's input.

I've just checked my car and you're right.

Originally Posted by goltho

What harm might be done to leave it wired the way I did it today as the workaround?

Provided that you've used a +12v ignition feed then possibly none.

The only remaining possible explanation is this from RAVE:
"The interface ECU monitors the two inputs it receives from the brake switch and checks them for plausibility. If the two inputs differ, the interface ECU disconnects the power supply output to the cruise control ECU to cancel/prevent cruise control operation for the remainder of the ignition cycle."

Maybe the brake pedal switch still isn't what the interface ECU is expecting?


Simon

[goltho]

Originally Posted by SD1too

Maybe the brake pedal switch still isn't what the interface ECU is expecting?

I can see that that's a possibility, in which case, that fail-safe function provided by the interface ECU will be bypassed. C0239-5 on the ECU will continue to monitor the brake operation from the LSM side of the switch (C0775-4) and go into suspend mode as it should (and does). It will depend solely on the brake light circuit for braking disconnection; on the other hand, if (e.g.) the switch fails, the LSM treats it as if the pedal is depressed, and so will the cruise ECU.

On balance, I'm still doubting the replacement brake switch not being the 100% correct one. We'll see though. (I'd far rather try changing the module in 15 seconds of comfort than draw more blood and bruises changing the brake switch yet again!!!). I didn't mention that the replacement I got from Rimmers had a manufacturing fault (one of the retaining clips on the holder was missing) which wasn't spotted until my mate took it out the bag to fit. I had to return to Rimmers to exchange it which wrote the day off and meant I ended up fitting it myself!! See - it is a conspiracy.

Dougie.

[SD1too]

Originally Posted by goltho

It will depend solely on the brake light circuit for disconnection ...

What about the brake pedal status switch: C0075-3 to C0895-6? The quote from RAVE mentions both.

Originally Posted by goltho

I'm still doubting the replacement brake switch not being the 100% correct one.

So am I. But that's not the fault of any contributor to this thread. The EPC descriptions are nonsensical. Since your brake lights work and so does cruise, there's a case for cutting your losses and supplying the cruise ECU independently of the interface ECU.

Simon

[goltho]

Originally Posted by SD1too

What about the brake pedal status switch: C0075-3 to C0895-6?

Good point, well presented. That was my bad - I misread pin 4 for pin 3 on C0775.

Originally Posted by SD1too

So am I. But that's not the fault of any contributor to this thread.

Oh absolutely!

Originally Posted by SD1too

The EPC descriptions are nonsensical. Since your brake lights work and so does cruise, there's a case for cutting your losses and supplying the cruise ECU independently of the interface ECU

We'll know soon enough when I fit the new interface tomorrow. There's no guarantee that doing yet another brake switch replacement will resolve it either, and so long as the car doesn't go on fire and the cruise control goes off when I brake, I'll be happy.

Dougie.

PS: Any comments from firefighters and/or electronics engineers are welcome. Undertakers need not apply.