electronics fault light

[dnl_303]

Hi there,

My electronics fault light has come on again on my 2004 signum 2.2dti. This had been coming on lately, but I had diagnosed this down to two blown glow plugs which i had replaced and fault light was not coming on again.

However, fault light is now coming on again. I have checked the glowplugs and they are all OK. The fault light only comes on about 10 seconds after I turn on the ignition when the engine is still cold. The light then goes out after about 30 seconds, irrespective of whether I start the engine or no. Once the engine is not cold, it will not come on. I can also make the fault light go out quicker by turning on the engine and revving slightly.

I suspect that given this pattern, it most likely has something to do with the diesel pre-heaters. I also suspect that there might be a blown relay or something of the sort that is causing a fault in the circuit. All fuses are OK.

Can anyone please tell me where to find the glowplug relay/s and how to possibly check whether the relays are ok or no?

Alternatively, any other ideas as to what could be trigerring this fault?

Cheers,
Daniel

[Telly Addict]

Sorry I can't help you Daniel, but it sounds like you are on the right path!

[James24]

I didn't have to replace mine - new glowplugs did the trick, but I think the glowplug relay is the metal box with cooling fins that is attached to the side of the battery box. The top of it is about 2" by 3" in size if I remember correctly.

I am sure someone will confirm/correct soon...

[dnl_303]

Yeah - I know which box you are referring to - but I thought that was the timer box rather than the relay itself. Or would that be one whole built-in thingie?

Also....just to confirm - I am checking the glowplugs using an ohmmeter and checking for resistance - all of the glowplugs are giving a reading of 0.27, which is fine I think. New ones are giving that reading anyway and old blown ones were giving a reading of 1.

Just wondering whether the glowplug can still be blown even though it is giving a low-resistance reading.

Cheers,
Daniel

[James24]

Yeah - I know which box you are referring to - but I thought that was the timer box rather than the relay itself. Or would that be one whole built-in thingie?

Also....just to confirm - I am checking the glowplugs using an ohmmeter and checking for resistance - all of the glowplugs are giving a reading of 0.27, which is fine I think. New ones are giving that reading anyway and old blown ones were giving a reading of 1.

Just wondering whether the glowplug can still be blown even though it is giving a low-resistance reading.

Cheers,
Daniel

I guess you've fixed this by now. Just in case, if one or more glowplugs has blown, replace the lot because some others might not be far behind. I tried to check mine but the ones that looked damaged weren't the ones with low/no resistance and I didn't think about it too much because they were all heading for the bin anyway.

The module at the side of the battery is the pre/post heating system control unit. I can't find anything that says if this is also the relay or if there is a seperate relay. I would think that parts department at a dealer could tell you which is the case, or at least what parts they generally sell to fix this problem.

However, if you are no sure if this is the problem or if a new control unit is expensive then getting the fault code read might be the best bet before you spend time and money on things you don't actually need.