306 HDi Won't Start

Post by **DHallworth** » 15 Apr 2011, 22:09

Guys,

Having a spot of bother with a 306 HDi and need your advice...

The car was running ok on Wednesday, started ok, was driving ok, etc but the cabin heater stopped working when my brother was out in it.

He tried to start it tonight and it's turning over no problem at all. However it just won't fire.

I've had it on Peugeot Planet this evening and it's showing that it's unable to communicate with the engine management ECU and the BSI is showing a fault code for no communication with the engine management ECU.

I've noticed that you can hear the heater running very quietly for around 30 seconds before it shuts down too.

I've cleaned the multi plug on the ECU and reseated it to no avail.

Anyone got any ideas?

Ta in advance!

David.

AndersDK · Post by **AndersDK** » 15 Apr 2011, 22:15

Check all system fuses.
There are quite a few separate fuses for both boxes.

The Birdman · Post by **The Birdman** » 15 Apr 2011, 22:43

Try and reconfigure the engine ecu

Post by **DHallworth** » 16 Apr 2011, 20:03

I can't do anything with the engine management ECU as the diagnostics machine can't even locate the ECU.

Does anyone have a wiring diagram for the 306 HDI?

Checked all the fuses too, none blown. Removed them all and reseated them to no avail.

Thanks

David.

Post by **CitroJim** » 16 Apr 2011, 21:03

David, if the Lexia can't see the ECU then this suggests the immobiliser has not done its job or there is a voltage supply missing to either the ECU or the immobiliser transponder.

This is exactly the same symptom as happens on MKII Xantias when a wire in the loom that runs across under the rad gives up and deprives something of critical volts...

I can imagine there could be a similar troublesome loom in the 306...

Another thing worth checking will be the double injection relay...

Do you have any indication on the dash to indicate if the immobiliser failed to deactivate on ignition on? The RFID chip in the key could have died or the aerial around the ignition switch may be duff or simply misplaced and therefore unable to read the key chip...

dieselnutjob · Post by **dieselnutjob** » 18 Apr 2011, 13:25

I always thought that the HDIs will power up the ECU enough to talk to the diagnostics even if the immobiliser is immobilising. It does sound as though the engine ECU simply has no power.

Post by **DHallworth** » 23 Apr 2011, 02:22

I've been looking at this again this morning and the Lexia can now interrogate the ECU without any problems.

However there weren't any interesting fault codes stored on the ECU.

There's a great flow of Diesel to the fuel filter so I decided to check the flow of fuel to the injectors...

I cracked an injector on the car today and tried cranking it and got a measly spurt of Diesel from it. I did the same on the 406 HDi we've got and got a right jet of Diesel from it.

This leads me to believe that it's the high pressure Diesel pump that's probably at fault.

David.

Post by **DHallworth** » 24 Apr 2011, 23:07

Righto, timing belt changed and high pressure injection pump changed too... No change, still won't start.

Anyone got a wiring diagram for the 306 HDi?

David.

Toby_HDi · Post by **Toby_HDi** » 25 Apr 2011, 00:00

Can you hear the lift pump in the tank priming when you switch the ignition on?

The HP pump won't kick in until a specific fuel pressure is reached. This is provided by the LP lift pump in the tank.

They are one of the more common HDi foibles.

As for a wiring diagram, which bit of the system are you after? What year is said 306?

Post by **DHallworth** » 25 Apr 2011, 01:32

This one's a 2000 306 HDi.

Am gonna have a fiddle with this a bit more in the morning and see exactly whats going on.

David.

Deanxm · Post by **Deanxm** » 25 Apr 2011, 08:34

David

If the injectors are not firing correctly then the rail sensor is not seing enough pressure, either because there actualy isnt enough pressure or because or a duff sensor. have you tried swapping the rail pressure sensor? or regulator?

I found this when helping a friend on a 306 HDI, it would fire the injectors but only wiith enough voltage to make a noid light faintly flicker, its like the more pressure there is the more voltage the injectors recieve when cranking.

As Toby says is the lift pump working at about 1bar and are the pickup filters clear?
Did you resolve the no dialogue issue with the ecu? that does sound like some power has gone missing.

D

Post by **RichardW** » 25 Apr 2011, 09:50

As above, check the live data on the Lexia when cranking. If you are not seeing 120 bar on the rail then it will never start - the ECU won't start injection till it sees 120bar. No idea how you can check they're working though... It also needs to see and make sense of the cam timing before it will fire - but I'd have thought this would flag a fault if it was AWOL, but again worth a check on live data.

Post by **DHallworth** » 05 May 2011, 17:31

Well we gave up on the car on Tuesday night as it just wouldn't start and the ECU wasn't responding.

We towed it to the dealer, they've done diagnostics on it, checked the wiring etc, and they've diagnosed the ECU faulty. We've been using them for 5 years and I trust their judgement. They're not the usual Mickey Mouse dealers.

If I buy a salvage 306 HDi, can I take the ECU and the transponder from the key and put them into my brothers car? Or can you unlock any HDi ECU?

Thanks!

David.

wheeler · Post by **wheeler** » 05 May 2011, 17:48

DHallworth wrote:If I buy a salvage 306 HDi, can I take the ECU and the transponder from the key and put them into my brothers car? Or can you unlock any HDi ECU?

Yes but you would also need the BSI aswell though as the ECU, BSI & transponder key are all matched together. Remember if the salvage car has a higher milage then your brothers car will permanantly inherit that from the 'new' BSI. Remember if you go down this route to keep a note of the chassis & reg numbers of the donor car incase you need the confidential code to progam new keys etc in the future.
As far as unlocking the ECU goes it can't be done with Lexia/Planet but there are people out there that can do it by reflashing eproms inside the ECU's.

Post by **DHallworth** » 05 May 2011, 18:01

Any 306 HDi will have a higher mileage then this one as it's only done 55k miles.

There's a guy 15 miles from us who does digital mileage correction so that might be worth a look into as well.

Be handy to find an unlocked ECU though.

David.