406oc.co.uk

Picked up my new 406 this evening, 2002 HPi Executive

There were a couple of faults identified on the test drive and I've noticed a couple more since I picked it up, (I was happy as I got it for a song).

1. The fuel guage doesn't work.
2. The MIL was on and P0403 was stored.
3. There's a petrol leak from the area of the tank somewhere.

I was aware of 1 and 2 and was quite prepared to set about stripping down the instrument panel to look for dry joints and bad connections. I wasn't aware of 3 until I stopped at Sainsburys on the way home and brimmed the tank (because of problem 1) - no I didn't overfill I stopped at the first pump cutoff. I didn't see any leak at the petrol station, but when I got home and parked the car with the front end pointing down my sloping drive there was quite a smell and a trickle of petrol running down the drive (about 10 miles after filling up).

Fact "A" The dealer I bought the car from (Citroen main dealers) said they had tried to fix the fuel guage and had removed and renewed the tank sender unit.
Fact "B" The fuel guage doesn't work (See 1 above)
Fact "C" The trip computer also does not know how much fuel is in the tank. I.E. No Distance until empty figure (everything else works fine)
Fact "D" The petrol leak (See 3 above)
Fact "E" The EGR valve has been removed and renewed also by the citroen dealer.

If you're still reading this far, here's where I need your help & opinions

The trip computer doesn't get it's information about how much fuel is in the tank from the fuel guage does it? I'd assume that both the trip computer and the fuel guage get their info from the tank sender unit (directly or via the ecu?) I now suspect that the sender unit has not been fitted back into the tank correctly, possibly damaged and definitely leaking. What do you think?

RE the egr codes: I cleared the code and reset the MIL but did nothing else and the MIL popped back on again after only a couple of miles with the same code (P0403). So I followed the procedure here viewtopic.php?f=1&t=2062&start=34 to reset the ECU. I then drove for about 30 miles and no codes/no MIL Could it be that the Citroen dealer simply didn't reset the ecu after replacing the egr valve? I thought Citroen used more HPi engines than Peugeot - anyway time will tell.

There's also a miss, but a new set of plugs wil be going in before I look at that one seriously.

All comments and opinions welcome

Mud

Fuel gauge not working = french electrics. Nothing a few hours fiddling and chasing the wires won't sort.

mudcruzr wrote:The trip computer doesn't get it's information about how much fuel is in the tank from the fuel guage does it? I'd assume that both the trip computer and the fuel guage get their info from the tank sender unit (directly or via the ecu?) I now suspect that the sender unit has not been fitted back into the tank correctly, possibly damaged and definitely leaking. What do you think?

Nicely worked out. On the D8 the trip comp is between the gauge and sender. On the D9 I'm almost certain the sender is wired into the BSI, which feeds data to the gauge and trip computer digitally over the VAN bus

Change the thread title to include 'HPi' cos I know DaiRees has one which had a miss-fire but can't remember the fix (might have been the coil pack(s)).

I'd say they have definately disturbed something when fitting the sender. Get it back to them to sort it (they've sold you a car that leaks petrol - this is bad).

Welly wrote:Change the thread title to include 'HPi' cos I know DaiRees has one which had a miss-fire but can't remember the fix (might have been the coil pack(s)).

Done

Good man

Hello

Yeah the famous misfire.... have a read of this post from the Black Pearl viewtopic.php?f=1&t=3658&hilit=hpi+misf ... =45#p56774. That's what cured it for me .

I'd advise taking the plugs out (using the "special" bihex tool ), cleaning them and carefully gapping them to 0.9mm and putting them back following the Pearl's hints and tips on the coil pack.

Touching wood it's still fine since that day, in fact I haven't touched the ignition stuff since (11 months / 13K miles ago). Since then I've been travelling quite a bit for work and we've just done all the summer holidays and day trips and all that and the car is running like a dream .

Removed the pump/sender unit this morning and confirmed 2 things

1. That was definitely the source of the petrol leak, the pump/sender unit had been removed and the rubber ring / gasket wasn't seated correctly. Now sorted with a new gasket when I put it all back together.
2. The float arm was free to move and there was a nice smooth change in resistance from the empty position to the full position. Does anyone know what the readings should be?

My guess is now that the sender unit is OK, it's about as simple a device as you can get, there really ain't much that can go wrong with it. I did notice that now the fuel gauge gives a brief jump from empty up to about 5/8ths then back down to empty when the ignition is first switched on - I can't swear to it but I don't think it was doing that before.
I reset the BSI just in case, no difference. (interestingly, I didn't get a bong when I turned the lights on - should I have? - was the bsi reset successful? - how do I tell?)

Anyhoo, that leaves the cables and connectors between the sender & bsi as suspects (lift the carpets & check for damp would be next I guess)

Also when I reset the bsi my fault codes returned almost immediately I started the engine, the P0403 I had before, a P0400 (egr based too) and a P1601 wtf? I've cleared them and am just about to go and re-initialise the engine ecu again, I'll post later if they stay cleared or not.

Mud

'tinternet wrote:P1601 ECM/TCM Serial communication error

Engine and transmission not talking?

Advice from forums relating to inferior, japanese vehicles seems to indicate that you should check connectors and looms around the gearbox

I'm not too worried about them, they cleared immediately and I've been giving it some wellie today and they haven't come back. Can it be that the codes are stored in more then one place and when I reset the bsi it polled all the other ecus for any stored codes? Dunno, but apart from the fuel guage and that irritating little missfire, the car is good.

mud