C15 glow plug problem

[Ben*17]

Hi all. Hope someone can help. Ive got a 55 plate C15 with glow plugs not coming on. I know the glow plug are fine, but for some reason the relay is not switching. At the relay there is a connector with 4 wires going to it. 1 is the earth, which is fine. There is 12v at another wire when the ignition is on. I think the problem is with the other 2 wires, which seem to come from the ECU. One of these wires has about 1v when the ignition is on but he other has nothing at all. Does this mean there is a problem with the ECU? Any help would be much appreciated, I have spent many hours trying to figure this out but have not made any progress.

Cheers

Ben

[jgra1]

Ben, where are you? I think the diagnostic lexia may have a test for this relay.. someone else will help more, I am learning as of today!
a few of us, well a lot of us, have lexias - which I think you may need to help with this problem

I don't know what engine the C15 has.. but my C5 Hdi wanted to power the glows this morning (about 5C) and didn't at lunchtime, 15C ... so the ECU may choose to fire them if it seems cold enough>?

John

[myglaren]

Two thoughts John.

1 - is your temperature sensor reading correctly and can you display the temperature from the MAF?

2 - Does the coolant temperature indicator function correctly.

I haven't experienced anything like your problems but I did have very poor performance when I bought this C5 and it was partly due to an engine temperature sensor (neither the MAF nor the coolant one) although the coolant temperature indicator would go a bit doolalley now and again.

Also, neither of my C5s lit the glowplug indicator at temperatures above freezing and even then only briefly. Car starts at sub zero temperatures just as it does in summer temperatures.

[jgra1]

Steve, I have never seen my glow plug light.. but I think its a yellow herring.. I do now think the GP's are active on a C5 Hdi at 6 or 7C and below, even without a light,., just a theory,,

not sure that will help Ben but..

[falling-out-with-my-car]

Ben,
I wonder if it is the cable junction under the front of the battery tray that has become seperated?
If the battery clamp has gone walkies a while ago it allows the battery to shunt forward on its tray disconnecting some major wires beneath there is a Blackjunction box linking all the major power leads together.
we had a similar problem with my sons 2000 reg C15 last year but this presented with no power at all on ignition.
might be worth a look?
regards
Nigel.

[Ben*17]

Thanks Nigel. I think I have been fiddling with that junction today, but I will check tommorrow.

[falling-out-with-my-car]

Ben,

with ours it was possible to just pull the junction forward enough to reconnect the leads
together working in the tight space between the back of the headlamp and the battery.


Nigel.