2.0 HDI (53 plate) Glow plug relay

[RossMac]

Hi there could anyone advise me where the glow plug relay is loctaed and if its in a box with other relays which one it is.

Thanks

Ross

[jasper5]

The glow plug relay is built in to the ECU. That's what my book indicates anyway.

[RossMac]

Thanks for reply jasper,

the problem is that its difficult to start on cold mornings (obviously)
have fitted new glow plugs (never helped)
clipped meter on to neg of the battery and turned ignition key to position 2 and checked for voltage at glow plugs
nothing !

That is when i asked the question about the relay, but i now have discovered that when the car is running i have 12v at the glow plugs
so I'm assuming when the engine is turning over there is 12v at the plugs.

1, i know it would be daft, but is it possible that the engine needs to running to have the 12v ? I'm sure i read something about the HDi not having a pre-heat or words to that effect.

2, if the problem is the relay and it is internal to the ECU, is this as major as it sounds ?

i was thinking if it was i could take a 12v feed direct from battery to spring return push switch (like a door bell switch) and use it to energiise the coil of an external relay, and run the s/w wire from the switched relay contact on to the 1st glow plug and it would link across the other glow plugs through the existing wiring, so it would get 12v as long as i was pressing the buton in.

let me know your thoughts or any other ideas you have would be much appreciated.

Ross

[RossMac]

I found the text about the pre-heat
http://peugeot.mainspot.net/peugeot_406.htm


Just for info

The 406 was most commonly supplied with a diesel engine. The original turbo diesel engine was replaced in 1999 by the superior HDi unit. Although the HDi offered greater refinement, noticeably improved fuel economy, plus a common rail system (which means the engine does not have to be preheated before starting), the HDi engines tended to lack the performance of the old turbo diesel range, with one exception being the 2.2 L HDi. By 1998, the 406 was one of the most popular diesel cars in Europe, an accolade it still boasts in 2006, fully ten years after its launch - a time when most other cars are starting to fade.

Ross

[jasper5]

Strangely, my Expert HDi van refused to start this morning (haven't used it since thursday), the battery was a little sluggish so I rolled it down the hill on my street....it started in 10 yards.

My wiper switch gave up as well, £32 from the dealer.

I did a lot of running around today so the battery has been charged, i'll see how it is in the morning.

The book shows the relay as being in the large plastic box on top of the inner wing, as far as I know the ECU is in there.

Maybe your problem is down to battery power, mine always needs a longer turnover of the starter on cold mornings and if the battery is low it won't start.

[RossMac]

Think i might have found something interesting, this morning before i tried starting, i lifted the bonnet and squeezed the primer bulb a few times it was soft and empty after a few pumps it became hard as it filled up with diesel,
The car started no problem after this, Im wondering if there is a non return valve passing, allowing the diesel at the filter to run back to tank.

Will monitor and report back.

Thanks again your info and input

Ross

[Captain Jack]

Primer bulb? On an HDI? You must have a Siemens system without the in-tank fuel lift pump (one less thing to go wrong)

[jasper5]

My 406 had the primer bulb, but my Expert does not.

My Expert van started first turn of the key this morning, so mine is obviously related to battery power.

[RossMac]

Definately a fuel problem, had to re-prime this morning, as soon as i did this it started no problem, must be air getting in to fuel system somewhere between injectors and inlet to fuel filter.
just have to find it now.

Thanks for info and input much appreciated.

Ross

[dorian105]

need some help here please. got a 2001 406 hdi, similar problem to the above,(cold weather wont start). changed the glow plugs, relay, fuel filter, coolant temperature sensor but still cant get around it. the glow plug light only comes on for a split second when car is cold and nothing happens. if engine is hot the light doesnt even come on. been push starting the car for the past week. it doesnt have any proplem when temperature around 10 degree. help please.....

[Captain Jack]

Have you checked the voltages running across the glow plugs when they are supposed to be on? Could be an electrical supply problem.

[Welly]

What about the in-tank lift pump? might not be working properly (especially in this cold).

The glow plug light only comes on for a split second anyway - it'd have to be about minus 20 degrees before it comes on for any longer.

[dorian105]

gonna check the voltage today, but it seems like the glow plugs work. going to get it checked again today at my mates garage. hopefuly is not a compression loss. thanks guys.

[MichealKnight]

I've been attempting to find out why my car did not start especially in cold weather, but even if the temp drops to 12 degrees. Anything around that temp and the car labours to start (at least 3 long attempts)....have changed glow plugs..no difference...also bought starter motor and glow plug relay. Changed starter motor today and Boooom...starts almost immediately.... problem solved. Hopefully this is helpful information. May not change the glow plug relay...although I have noticed the heater/coil light on dash does not come on....it did when I first bought the car. Is that a problem?

This also may be a silly question...but why does the common rail Hdi engine need glow plugs if the engine does not need to be preheated. What purpose do the plugs serve?

thanks Jon.

[steve_earwig]

They do need some preheating, just not very much - when it's warm it's so quick you won't even see the light (hint, hint...)