406oc.co.uk

I am driving a 2.2 HDi estate - remap&defap etc, very close at this point to moving onto a 508 SW after a long time in 406's

Anyhow i randomly get the EML light and a bit of a limp mode, well to be fair for a car that supposedly on the most powerful remap file for a 2.2 hdi it feels a bit sluggish.

The fault codes that i get are:
"Intermittent fault. Turbo pressure signal. Short-circuit to postive, open circuit, or value too high"
"Intermittent fault. Accelerator pedal blocked. Strategy activated"

I recently tried a carbon cleaning process for the car and got the fault the other night, the light went away again but i suspect the turbo pressure signal fault is still there. Just wondering if there is a quick fix for it, or is it a job that needs the turbo vanes to be inspected and cleaned?

To be honest Frank it could be several things...

It does sound like an over boost issue - so I would be tempted to check the vacuum pipes with a vacuum gauge ( if you have one ) and then bypass the swirl flap by unplugging the vacuum feed and bunging the end ( the ball on the end should be in the default 16v position )

If you have a bit of money to spend, it's worth replacing the MAP sensor, and the MAF sensor - it might not fix the issue but it certainly won't do any harm.

When I had the P0238 code, it was resolved by replacing the vacuum pipes with eBay 3mm silicon ones - and binning the 3 way restrictor as it was blocked.

My P0235 code wasn't fixed, but a member on the Coupe club had the same fault and a new MAP sensor fixed it.

+1 overboost is most likely to give you this behaviour, likely cause is lack of vacuum / vacuum leak.

The pipe to the MAP sensor can get damage, it's worth checking.

Using the cruise control resume function instead of flooring the throttle pedal might eliminate the Accelerator pedal blocked fault as the cause.

Both faults are intermittent - have you tried clearing them and trying to work out what brings then back?

I had a quick look today, the ball joint for the swirl flap has snapped, and i see that a number of the vacuum pipes are cracked looking. Ordered a few meters of 3mm hose on ebay and will need to fix the swirl flaps. What position is 16v; towards the radiator or the bulkhead?

Also this 3 way restrictor what part is that now?

The usual 2.2 HDi mods were done defap, egr removed, air doser is gone but i recall some saying something about simplifying the vacuum system.
What else can be removed?

Hi Frank.

I did a how to (on the Coupe club) about simplifying the vacuum system - as you are already defapped and deEGR it's much easier, though the next step would be to get some Nico pipes which will eliminate the potential leaking of the air doser.

If the swirl is upright - towards the radiator - this is the 16v position. If you could fix it in this position it may not flag up any more faults.

The 2 way restrictor is the black adapter on the vacuum pump (iirc) and is removed by squeezing the tabs. This restrictor has 2 outlets, one is unrestricted to feed vacuum to the servo - the other 1 has a tiny hole to limit the amount of vacuum used for the other EVs.

The 3 way adapter I think is on the servo end - but honestly it's been so long since I have seen an OEM layout that I could be mixed up.

Basically I binned the 2 way restrictor, and used the 3 way directly off the vacuum pump - 1 feed to the servo ( must be unrestricted 1 feed to the turbo ev and 1 to the swirl ev.

You would still need to keep your vacuum reservoir for your doser - so your layout will be different.

http://www.406coupeclub.org/PHPBB3/view ... 45&t=49159

Edit - link to KrisB pipe pictures... The saloon or estate only needs the manifold part - not the straight tube.
http://www.406coupeclub.org/PHPBB3/view ... +b#p530705

Any questions, feel free to ask.

Hi Ginger

Forgot to say i have the air doser bypass, made a batch of them at a time, doggy got one hope the welds held

Thanks for that link, look forward to trying this.

In that case, just following guide with your replacement pipe - although your ball will still need replacing, or fixing in the upright position.

If the car is still a bit sluggish, I would suggest you replace the MAF - don't bother unplugging it as this doesn't help on the 2.2hdi, it only seems to work on the 2.0hdi.

Good luck.

FarmerPug wrote: ↑Sun Jan 26, 2020 11:08 am Hi Ginger

Forgot to say i have the air doser bypass, made a batch of them at a time, doggy got one hope the welds held

Thanks for that link, look forward to trying this.

Never got fitted unfortunately - it was for my bro's last 2.2 406, but he managed to snap off one of the studs holding an injector into the head while trying to cure a leak so it got scrapped. (He's now cursing a 2.2 407 to all within earshot).

I never got the chance to test this theory, but I think a vacuum pump to servo pipe etc from a 110 HDi would be spot on for simplifying to 2.2 layout.

I did away with the swirl flap actuator on my last one - with the 6-speed box the engine didn't turn fast enough at 70 to swap it to 16 valve mode.

Please give your car a decent try fixed in the 16V position before thinking about spending money on a replacement, I'm sure you don't really need it and it lets you get rid of even more plumbing - you'd then only need the turbo control EV, the other 4 plus reservoir are redundant.

GingerMagic wrote: ↑Sun Jan 26, 2020 11:29 am In that case, just following guide with your replacement pipe - although your ball will still need replacing, or fixing in the upright position.

If the car is still a bit sluggish, I would suggest you replace the MAF - don't bother unplugging it as this doesn't help on the 2.2hdi, it only seems to work on the 2.0hdi.

Good luck.

Sent a PM across Ginger, ive followed the guide as much as i can but stuck on a few points, just wondering i still have an unused pipe there at the servo when using the 2 port connector.
What happens to the two other electrovalves up at the bulkhead.
Also there was an electrovalve that had the blue connector there below the air filter housing just wondering where it goes.

Im in the process of rebuilding the rear brakes now so the car is off the road for a while yet while a rebuild kit comes, K12 micra in the meantime

I'll reply shortly, once I've received it..

I kept the 2 way adapter on the servo end as a spare inlet/outlet for testing purposes - then once I was happy I had no leaks I used it for a vacuum gauge fitted in the centre heater vent ( along with a boost gauge )

Is far as I can remember - there are 2 solenoids with blue connectors under the air box, one is bolted to the engine which is the swirl, the one actually fitted to the air box I believe controlled the air doser inlets.

You'll need to keep the wiring to the solenoids connected to keep the ECU happy, unless you get them mapped out in the future - Srdans IQ93 is a great addition.

Again, it's been so long since I have seen an OEM set up - most of this is from my tired memory..

I love the K12 - I drive my Mum in laws automatic and it's a blast..!