Limp mode

[Ammar786]

Hi folks I have recently purchased a 2.2 hdi
But it keeps going in limp mode I had the fault codes read
1was the maf sensor so I replaced and that cleared that fault
1 was the turbo pressure signal or map sensor so I was told so I replaced that
But it's still in limp mode

Codes that are still on are
P0403
P1435
P1442

The dpf or fap has been removed from the exhaust and now has a straight pipe


How do I do the egr delete is there a thread on how to remove it

I also noticed the swirl flap actuator isn't working
Does someone know how to troubleshoot the vacuum system and test for leaks on components

Any help would be great thanks

[Doggy]

Hi & welcome aboard.

Your problem is almost certainly overboost, caused by a vacuum leak - the turbo actuator needs a working vacuum system to regulate the boost, without it you'll get too much and it will trigger limp mode. (Chances are it will clear if you do a few journeys very gently).

There's plenty of relevant info on the forum, just use the search function.

Have a look at this thread of mine for egr delete: viewtopic.php?f=1&t=21954&hilit=took+the+plunge

[GingerMagic]

Hi, welcome

If your swirl flap isn't working then this is likely to be the cause of your other vacuum issues, as the diaphragm splits and loses the vacuum...

I think overboost is a P0238 code, the P0403 is your EGR - is it unplugged?

The last two are for the additive, did you have the car remapped after the removal?

[Ammar786]

Thanks for the reply

Right I have done the egr delete and removed any redundant vacuum pipes
I have also replaced the swirl diaphragm

Yes the car has been mapped but now sure if it has been done correctly

The car still has the eml light on and still goes in limp mode

What can I do to fix the problem

Is there anyone near me Ts17 postcode that has Peugeot planet that can help me out as I'm really confused as to what the fault could be

[Doggy]

If you had the fault codes cleared and the ones you list are those that came back, (I think that's what you're saying?) and you still have additive system faults present, then your engine ecu is still 'talking' to the additive ecu. (Meaning the dpf has not been deleted from the engine map).

Unfortunately you're a long way from anyone we know of that could help, (but maybe there's someone on the coupe forum http://www.406coupeclub.org/ ).

Failing that, are you brave enough to flash the ecu yourself, or know someone who you would trust to do it for you?

Edit: I see you've already discovered the toupe forum.

[Ammar786]

thanks for the reply doggy

right the codes I mentioned first were before the remap, I did all the work like removed the egr etc and followed finchys guide on how to simplify the vacuum system.

I will have read the new fault codes today and find out for definite what is going on, but my suspicion is turbo pressure faults possibly over boosting
I noticed yesterday there was some oil coming from the bottom of the intercooler and there was some air bubbles when revved, would this cause a limp mode problem if the intercooler is leaking.

[Ammar786]

are you brave enough to flash the ecu yourself, or know someone who you would trust to do it for you?


what do I need to flash the ecu how hard is it to do, I have ktag (kessv2) software I can use to read the ecu if that is of any use

[Doggy]

Oil & bubbles around the base of the intercooler is pretty typical, doesn't normally cause a problem.

Overboost is almost always due to a vacuum leak, but they can be buggers to find.
Another possibility is the restrictors in the vacuum pipes - each of the branches from the main vac pipe between the vac pump & servo has a restrictor, (a metal blank with a hole about 0.5 mm diameter through it), to prevent a leak from stopping your brake servo working. Worth poking a strand or two from a bit of electrical flex through each hole to prove they're clear.

Failing that, simplify the vacuum circuit even further for test purposes - it should work with only the vac pump / servo / turbo electrovalve / turbo connected. That's how mine is all the time.
(The air doser will default to opening the valve between the intercooler and inlet manifold, the swirl flap diaphragm will default to using all 8 inlet valves and you're not using the two for the egr).

PM sent BTW

[Ammar786]

hi mate
thanks for that response.
i have allready simplified the vacuum system to a how to guide on the coupe forum thanks to finchy.

but it still has some faults.

i took a fresh read of the car today and the following fault codes popped up

p1435 additive system
p1442 additive quantity
p0403 exhaust gas recyling circuit. open circuit
p1429 differential exhaust pressure signal
p0235 turbo pressure signal
p1537 accelerator pedal jammed
p0100 flow sensor signal

i dont think the dpr and egr have been dissabled hence the faults

what software do i need to remap the ecu with the files you have