Idle control valve

Does anyone know the voltages that are fed to the ICV and what pins they come off from the ECU?

ICV has been replaced at the moment with a rad valve as I think I have a broken wire somewhere between the ICV and the ECU.

It'll hold a nice idle once hot but does it no favours for cold starts. Be nice to get the ICV working again.

If it's the same as on the A610, it has a centre tap which is earthed and two 12v inputs. One to pull it open. The other to pull it closed.

The ECU balances these to open or shut it a variable amount by PWM.

Andrew

So had a look with my multimeter and I don't think I'm getting the 12v feed to the middle pin. Assuming this is correct then there should be a 12v+ to the middle pin, one should get its feed from the ECU and the other be the -ve (earth).

Problem is it's not clear which is which.

I think the +12v comes from a relay in the ECU cubby hole looking at an old thread, but typically all the pictures are lost thanks to Photobucket. JonC????

[mettersl]

Darren,
If you look on line, there are photobucket defeat add ins for chrome so you can get the pictures back.
Lee

........ I think the +12v comes from a relay in the ECU cubby hole looking at an old thread, but typically all the pictures are lost thanks to Photobucket. JonC????

Darren ...... I think you will find that the 12v for the ICV ... (center pin 2) ..... comes from the Fuel Pump Relay (in the ECU cubby hole) which will only supply 12v whilst priming, and when the engine is running.
If you just check with just the ign switched on, there will be no voltage except when priming ....... so you have to be quick.
The pin numbers on the ECU for pins 1 & 3 of the ICV connector, are 23 & 24 respectively.
BTW ..... what year is your Alp ........ Different model year Alps call the ICV different names ....... none of the electrical manuals call it an "Idle Control Valve", not even the main W/S manual does. Not knowing the Turbo that well ..... (not at all really) ..... I hope I have picked the right one by cross referencing.
John

John. I'll say it again, you're a genius. Thanks again as always. Pin 23 on the ECU had been bent and wasn't making proper connection. The little tab that keeps it in position had been folded over so it was moving back in the multi-plug as it was pushed home. Car's all idling nice once more. I'll test again tomorrow but all looking good.

For interest here's a small guide I found on the ICV (or whatever they're called by Renault John? I don't know either) and how to test.

https://www.justanswer.com/volvo/2f4ka- ... e-bad.html

You can learn a lot from John. Far easier than trying to work it out yourself.

Well done Darren, pleased to have been of help.
Oh, and BTW ...... next time, let me know the model year of your Alp ..... seriously though, to any other member reading this that wants to posts an electrical question, ...... as there is a different electrical manual for each model year, it helps to know which manual to pick up as there are various changes in most years.
Rant over.....
John

Haha. Well just to complicate things John, mine's technically an '88 car, but an '89 type build I believe - cross over time. Never simple with these cars is it.

Ah whoops. I realise I told you wrong but no matter now! I'm rather tired due to a new baby so making a few mistakes. 12v centre. Earth either side...

Apologies if I misled you.

Andrew

Well I thought I had it sorted but tried it from cold again at the beginning of the week and I'm getting the same issues.

Completely rewired from pin1 and 2 to ECU pins 23 and 24 but still no joy. Does anyone know, or can anyone test the voltage numbers they're seeing at the ICV connector? I've tested the ICV itself with a 9v battery and I can make it flick fully open or closed by joining the +ve to the centre pin and -ve to pins 1&2.

I'm not sure if the mechanism by which it works.... I assume the voltage fed back and forth from the ECU is kept in balance by a feedback mechanism so it sees different voltages either way to open and close the valve. I've got 13.5v at the centre pin, 4.4 (ish) at pin 1 and about 0.4 at pin 3. But they don't seem to be varying...

I wonder if the motor part of the ICV is working but it's not feeding back to the ECU??

New wiring...

[mettersl]

Darren,
Have you tried exercising the valve off the car...they do sieze....with all the wiring information you now have it should be simple to test it off the car...I think brake cleaner can be used to free up a sticky one.
I have a second hand one somewhere if you want to try a swap.
Cheers
Lee

No it's all working fine Lee as it's relatively new and I've cleaned it just in case. It's either fried or getting the wrong signal.... hmmm.

Success. Back to first principles.

This issue first happened when we were at Scoff's pre Xmas tune. My thinking was that the wiring had been disturbed and that had caused the problem. However this also coincided with the ECU coming out and chip being replaced for the tune.

Pulled the ECU out and carefully looked at the wiring on the 'chip stack. Turns out one was loose. Re-soldered two wires in the end. Perhaps not as pretty as Mr Faulks soldering but hey presto.

Plus added benefit of two new wires in the loom to replace the originals.

Nope. Problem is back again tonight. I'm now thinking it's the ICV but it'd be nice to know what voltages other people see before I buy a new one.

I'll have to cancel the MOT on Friday as well as I'm not happy giving them a car that struggles to run clean for the first 10 mins.