Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault

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Mon 17 Jan 2011 15:59
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

Here we go again! (see similar threads from Whatdowepayourroadtaxfor
8 Dec 2008)

EVERY time any service garage changes the oil filter, the message " anti polution fault" appears when I drive away, the engine management light stays on, the car goes into "slow" mode (max 3000rpm, then later it's allowed full revs but still with fault on), the engine 'runs on' after switch off, and the garage guy says "..just give it a long hard run and it'll be OK..."!

It often is, but not this time. The "fault" Is on and off like Jordan's relationships.

At the same time, there's diesel dripping out of a fuel ine feeding into / out of, what I assume is (a 70mm x 40mmx 40mm oblong plastic case with a 2 pin connector) the pressure regulator solonoid, above the pressure rail (Bosch system), although no 'diesel experts' seem to recognise this discription, but one is going to look at it the leak problem in the next few days.

This 'thing' / solenoid actually continues to make a noise well after the engine stops (minutes) and it was still operating two hours after I switched off when I checked under the bonnet the other night to try and ascertain why the battery keeps intermittently draining overnight.

Maybe that's why! How much current does this soenoid take, and why does the system, after ignition etc. is switched off, car locked etc, have a live power feed to it ?

This draining the battery fault is intermittent, can't be traced by any autoelectrician, and is also driving me daft. No intermittent shorts, lights on etc. etc. anywhere I can see after a thorough examination. I've also re-set the BSI.

Any suggestions?

Thank you guys

Edited by Whatdowepayourroadtaxfor on 17/01/2011 at 16:04

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Wed 19 Jan 2011 00:49
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

I now know that the item that leaked diesel, mentioned above, was the Fuel Pre-heater unit, which, according to the garage guy, are '...always going faulty, and we usually fit a bypass kit...'.

They fitted a bypass kit, and it became apparant that the Fuel Tank pump is running intermittently when the car is not running, ignition off and car locked, which might finally explain the intermittent battery drain and even the leak itself?

They contacted an autoelectrician re the pump situation, and he suggested '..the pink multi pin (multifunction?) relay next to the ECU might / would be the cause...'

Taking the car back (how much more was I going to need to spend???), I've found that there is an intermittent break / short in the part of the two part wiring harness leading to this relay, the part that has 4 or 5 of the relay connector wires in a 30cm. sheath (not the large corrugated plastic sheath), with only one of them seeming to teminate in a chassis earth bolt! Gently twisting that area of the harness 'unlatches' the relay and stops the pump when in it's permanent on mode as described, and, oddly enough, after I did this, the Anti Polution Fault message cleared and the engine is back to normal.

This is getting very complicated. Hopefully, when I strip back the sheath and investigate the intermittent fault, I'll be able to at least sort out the fuel tank pump over-run issue.

Can anyone tell me what the relay actualy does? It's got many (8 - 12) wires going onto the relay socket (one of which I suppose will be the latching coil) so it must be switching / activating a number of functions, or it my be that the relay housing contains more than one relay.

Does ANYONE understand the Peugeot 406 HDI system with any great certainty / authority?

Edited by Whatdowepayourroadtaxfor on 19/01/2011 at 00:53

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Wed 19 Jan 2011 13:42
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

Sorry...I should have said in the first post "Every time the garage changes the FUEL filter" not the "oil filter".

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Tue 1 Feb 2011 22:01
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

Conclusion:

The fault is in the 30mm diameter corrugated plastic sheathed wiring/cable loom from the ECU/EMS module on the left (next to the pink relay) .

The loom does a hairpin turn as it leaves the control module and then runs along the front of the engine, branching off to the many engine / fuel system sensors etc. plugs / sockets and to the large round "aircraft" plug under the battery holder.

This loom is VERY intermittent, and if even touched anywhere along its length produces both the fuel pump fault and the anti-polution fault.

Have checked the bundle of earth returns from the loom to the chassis, and all are OK.

I suspect there is at least two broken wires (or short circuiting wires) in the loom, and I feel sure they've been like that (intermittently) for the last 3 - 4 years, hence odd faults appearing after every service when the loom must be moved / touched to change the oil filter and the fuel filter.

The loom is now firmly strapped to the chassis at the "hairpin turn" via two cable ties, and the faults have been clear for the last few weeks.

I may venture to a breakers yard for a replacement when I figure out how many plugs / sockets need removing to replace it. Then again, is a "scrapyard replacement" going to have internittent s/c - o/c wires as well?

Antway it's great to have a fully charged battery in the morning and to not see the anti-polution fault message every other time I start the engine.

Hope this helps someone else! It's been bugging me for years.

.

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Tue 1 Feb 2011 22:36
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Peter.N.

It might well do. I have recently bought a 406 Hdi but so far have not had any trouble, not electrical anyway, I have got a Lexia - but don't yet have it functioning.

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Tue 5 Jul 2011 23:22
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

It's a great car and now reliable (appart from an intermittent ABS fault)...and just completed over 250,000 miles!!

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Mon 5 Dec 2011 10:41
Peugeot 406 HDi - Peugeot 406 2.0 HDI anti polution fault - Whatdowepayourroadtaxfor

Intermittent ABS fault mentioned now resolved.

See my other posting on 406 abs fault.

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