[new 2 tran]

I drove through a large puddle a while ago and the van went into limp mode when restsrted. Code 17964 negative deveation in pressure. So i,v changed all vacume pipesand no better so just put new n75 valve on cleared the code. Was ok until got it into 5th on motorway and back into limp mode and code is back. Any one got an idea what could be up with it. O its a 2.5 102 T4. cheers.

 

[Zmok]

Re: LIMP MODE

Negative deviation normally means the MAF sensor and the Boost pressure sensor readings do not correlate.

Negative deviation means you have a Maf reading that is normal and a low boost pressure.

Could you have a split intake hose or Intercooler split etc..

 

[JIMMYJAMES]

Re:LIMP MODE

Waterlogged air filter or as above waterlogged/damaged maf is my suggestion. New style wings with the vnts have a tendancy to draw in water, no such problems with my old girl! Good luck getting it sorted bud :ILU:

 

[new 2 tran]

Re:LIMP MODE

Its got new air filter on so i will check intercooler pipes and my mates maf. Cheers lads.

 

[JIMMYJAMES]

Re: LIMP MODE

Good luck getting it sorted :gl

 

[new 2 tran]

Re: LIMP MODE

Drove home today about 9 miles on back roads and lots of roundabouts van pulls hard after 2500 rpm but when on motorway it hits limpmode. Strange.

 

[Zmok]

Re: LIMP MODE

Sounds like overboost to happen under full load.

Check your wastegate and actuator.

better still run vcds and log the boost pressure.

 

[Monza]

Re: LIMP MODE

Mine does similar, fine bombing around town at town speeds. Hit a hill or a motorway and it goes into a weird limp where it only revs to 3k

 

[new 2 tran]

Re: LIMP MODE

Cheked intrcooler and pipes all look ok so blanked egr off went for drive and its flat as fart. Take blank off tha mora n try again.
It,s doin me heed in.

 

[Dazboi]

Re: LIMP MODE

Seen a few transporters with chaffed wires on main engine wiring loom. Maybe worth checking?

 

[new 2 tran]

Re: LIMP MODE

Good call mate looked at wire loom from bulk head to ecu and found two wires rubbed through a bit so fixed them. Took van out and it had less power than before so took blank off egr vavle and turbo pulls better from 2500 rpm.Any ideas what else i can try to get rid of this 17964 code. Thanks all.

 

[Zmok]

Re:LIMP MODE

Sounds like overboost to happen under full load.

Check your wastegate and actuator.

better still run vcds and log the boost pressure.

You need to do this. Throwing parts at it aint gonna fix it.

 

[new 2 tran]

Re:LIMP MODE

Is that the one you can down load from rosstech. Think i saw this somewhere.

 

[new 2 tran]

Re: LIMP MODE

Got vcds lite on laptop and came up with 17964 1556 -35-10 cant decode file not loaded. how can i scan while driving.

 

[Zmok]

Re: LIMP MODE

Boost Pressure negative deviation.

Looks like you may a problem with either the turbo, wastegate, pipework or N75

Still sounds like over/under boost. Have a good look at your wastegate, Actuator and connecting pipework.

Open up measuring blocks - click up the group numbers till you get boost pressure and Expected pressure - click on log then start

go for a spin!!!

 

[new 2 tran]

Re: LIMP MODE

Cheers ZMOK will try satda morn n see how i get on thanks.

 

[new 2 tran]

Re: LIMP MODE

Right had block 11 on its the nearest thing i could find. Cal pressure 1081.2 Act pressure1009.8 12.8% Then when in limp mode reading was same apart from 68.1%. i dont know what that means.

 

[Zmok]

Re: LIMP MODE

Log the readings then tank it down the road. Graph the data and post it up here.


Your data is fine for idle speed.

 

[new 2 tran]

Re: LIMP MODE

Cheers man i,l see if i can do it back from work as theres lots of roundabouts to give it a good boot.

 

[new 2 tran]

Re: LIMP MODE

Had it on means block 11 started it but when i have a look at saved data it says not running even when i,v been for drive.What is duty cycle 12.1 % then in limp mode it,s 68%.