Bitron location ?

[TopDonkey]

Does anyone know where i can find the Bitron relay on my 2002 peugeot 406 hdi 110 family estate ?

My engine temperature gauge hasnt worked since i got the car, and i thought it was down to a faulty engine temp sensor (the green one above the gearbox), so i bought a new one from the dealers today and fitted it and its no different, still no engine temp reading at all

the cooling fan doesnt run at all, even with the aircon on, but with the aircon on, i do get the stop light lit on the dash (indicating a fan fault i think ??), and if ii unplug the coolant temperature sensor the fan runs at full power, and if i turn the engine off with the sensor unplugged, the fan runs at half power, so i know that the fan runs properly.

So i think its a Bitron problem, but i cant find it anywhere !

[poddack]

You could try the blue one near the fuel filter

[TopDonkey]

do you mean the blue connector on top of the fuel filter ?, thats only a fuel temperature sensor in there, does it have anything to do with the coolant temperature display on the dash ?, i didnt think they were linked in any way ?

[TopDonkey]

I found out that my can doesnt have a Bitron fitted, most HDI's built after 1999 have a BSI (body systems interface) instead of the bitron, i'm still not sure how the temperature sensor and the dash temperature gauge are wired into this BSI, so if anyone can shed any light of wiring diagrams, they would be appreciated

Thanks

[poddack]

I was thinking of mine, thought it might be similar. There is a brown and a blue sensor directly in fron of the fuel filter. the blue one goes to the dashboard, the brown one goes to the fans (bitron) and the green one on the side goes to the ECU.

[Doggy]

I'm not certain on this, but it looks like you have only one coolant temp sensor, (whereas I believe D8's have 2?).
It has a 2-pin green connector, wire no.s 4000 white & 401 beige. Connects to ecu, pins 46 & 45. Ecu communicates with instrument cluster via vehicle are network. BSI isn't involved in this aspect, (but does control a/c compressor clutch).

Engine ecu pin 86, (active low), drives the 'engine management mutifunction relay', which in turn drives the low speed fan relay: Ecu pin 25 drives hi speed fan relay. Again, BSI does not appear to be involved in fan control.

HTH

[TopDonkey]

Thanks for responding, all info helps me, but i dont think the 2.1td is based on HDI technology, which means it has the old setup of 3 temperature sensors (i think) around the thermostat housing

I started with a Citroen BX with a 1.9td like that, then had a Xantia with a 1.9td (3 sensors again), then i bought a Citroen C5 2.0 HDI which has only 1 temperature sensor but has a bitron, and now i am onto my new Peugeot 406 HDI which has 1 temp sensor and no bitron, and a BSI computer which is completely new to me, and it looks like i might need to find a lexia or peugeot planet to interrogate the BSI to see what is wrong with it

[TopDonkey]

Nice one, thanks Dogslife, that will give me plenty more bits to check and trace round on saturday (i have to work tomorrow in brighton)

Did you get that info from the haynes manual ?, or do you have a workshop manual ?

[Doggy]

Haynes BOL