2 faults on my signum 2.2dti

**kenno31** · 12th May 2010, 10:23

Alright now i have been having problems with turbo lagging and sometimes not coming on atall then casr going into limp home mode, soi have cleaned the EGR valve and also found a vacume pipe from a solenoide with a split in which i have replaced, but still getiing problems, so i have just lent a op com system of a friend,
and it is showing up 2 faults they read
p0638-5B THROTTLE CONTROL CIRCUIT POSITIVE DEVIATION
AND
P0234-5B BOOST PRESSURE CONTROL POSITIVE DEVIATION

any suggestions what could be causing this? or anything else to check while i still hav ethis op com system??
cheers

**Celes** · 12th May 2010, 10:33

Clean the boost sensor and throttle body

Easy job on the DTi's.

**kenno31** · 12th May 2010, 20:37

cheers i will have a look at them,
I have also noticed when giving it a run today that the
EGR valve is asking for 100% and getting 95% which i would think is ok,
but turbo pressure is asking for say 110 Kpa its getting about 100Kpa but as it gets up to around 200Kpa demand its only reciving about 120Kpa any ideas??
The higher the demand the greater the differential? would this suggest im loosing pressure from one of my vacume pipe? pipe venting/sucking in air under high demand?

**Big Sig** · 12th May 2010, 20:43

Originally Posted by kenno31

cheers i will have a look at them,
I have also noticed when giving it a run today that the
EGR valve is asking for 100% and getting 95% which i would think is ok,
but turbo pressure is asking for say 110 Kpa its getting about 100Kpa but as it gets up to around 200Kpa demand its only reciving about 120Kpa any ideas??The higher the demand the greater the differential? would this suggest im loosing pressure from one of my vacume pipe? pipe venting/sucking in air under high demand?

As celes said, clean the boost sensor.

**macdad** · 12th May 2010, 20:43

?Have you checked the hose on the right as you stand in front of car...think its called the Intercooler charge air pipe.Mine(2.0dti) did similar,it had a split in the pipe.

**kenno31** · 12th May 2010, 22:01

yeah macdad i have had a look and cant see anythine obvious, ill get someone to rev the engine while i have a look around it and see if anything shows,
thanks again

**kenno31** · 18th May 2010, 16:48

Just for info, i replaced the lug on the end of vac pipe, the one i had previously repaired or so i thought, I got one of a scrapper yesterday and my car feels like a new one today pulling away much better, turbo is winding up at about 1500-1600 rpm where as it was about 2400rpm before,
Im going to clear the faults tonight then try to find out why my cruise control is not working,