VCDS-Lite Version: Release 1.2
Sunday, 31 May 2015, 15:33:26.
Control Module Part Number: 038 906 019 LR
Component and/or Version: 1,9l R4 EDC G001SG 1565
Software Coding: 00002
Work Shop Code: WSC 00020
VCID: 729759CB2DB7
1 Fault Found:
17964 - Charge Pressure Control: Negative Deviation
P1556 - 35-00 -
If any one could suggest a starting point or the most common cause the car seems to lack power but then it comes back doing my head in.
thanks in advance
Negative deviation means the car is expecting more boost then its getting from the turbo, although worst case could be turbo failure its FAR more likely this is caused by a leak in the pipework. You should amend you signature/profile details to tell us what variant of the diesel you have as the pipework is different between the 115 and the 130/150 however I've seen both the L shaped pipe at the turbo exit and the S pipe at the bottom of the downpipe have holes in them which have caused this...
thanks for the reply it is the 115 model
In that case I would start with the S pipe that joins the downpipe from the turbo to the intercooler. You'll need to remove the undershield and then you'll find a large aluminium pipe clamped to the drivers side of the engine coming from the turbo, the pipe from there into the intercooler.
thank for the reply I will have a look at that today and let you know how I get on.
thanks again
Could the negative deviation fault code not also be caused by sticking turbo vanes or defective vacuum control?
In reality it could be any of those things, work through the easiest items first.
Checked the pipework and all seems fine no leeks or anything..
defective vacuum control is that the n75 valve/switch
thanks again guys.
Yes the vacuum supplied to the turbo actuator is controlled by the N75 valve
changed n75 and vacuum hoses and car still same seems to be in limp mode all the time (wont reset after turning engine off).
also had turbo off it was fairly coked up cleaned it out now moves free no sticking
just had it round block with laptop attached these are the results from block 11
038 906 019 LR 1.9l R4 EDC G001SG 1565
Group A: '011
Engine speed Spec. intake press. Actual intake press. D.cycle MAP
TIME 2850-3150 2000-2150 2000-2200 40-95%
Marker STAMP /min mbar mbar %
0.69 903 979.2 805.8 19.9
1.41 1050 1040.4 795.6 19.9
2.13 1008 1009.8 795.6 21.9
2.83 1428 1009.8 785.4 58.6
3.55 1449 1009.8 785.4 58.6
4.27 1449 1009.8 785.4 58.6
4.97 1428 989.4 785.4 58.6
5.69 987 979.2 805.8 26.7
6.4 903 979.2 805.8 19.9
7.12 903 979.2 805.8 19.9
7.82 903 979.2 805.8 19.9
8.55 903 979.2 805.8 19.9
9.26 903 979.2 805.8 19.9
9.98 903 979.2 805.8 19.9
10.69 1050 1122 795.6 19.9
11.41 1008 1193.4 805.8 19.9
12.12 1092 1387.2 816 19.9
12.84 1638 2111.4 795.6 19.9
13.55 2121 2244 816 19.9
14.27 2667 2182.8 836.4 19.9
14.97 2562 989.4 836.4 38.6
15.69 1617 1040.4 816 57.8
16.41 1785 1275 826.2 19.9
17.13 1827 1020 805.8 49.8
17.85 1869 1152.6 795.6 41.4
18.57 2016 1907.4 816 19.9
19.29 2163 2172.6 846.6 19.9
20.01 2352 2172.6 867 19.9
20.73 2037 969 846.6 38.6
21.45 1554 1142.4 805.8 43
22.17 1512 1570.8 816 19.9
22.88 1428 969 795.6 58.6
23.61 1302 969 795.6 58.6
24.32 924 979.2 805.8 19.9
25.04 903 979.2 805.8 19.9
25.77 1134 969 795.6 58.6
26.48 1050 1458.6 805.8 19.9
27.19 1155 1591.2 816 19.9
27.91 1239 1632 816 19.9
28.62 1029 979.2 816 29.5
29.35 882 979.2 805.8 19.9
30.05 903 979.2 805.8 19.9
30.77 1176 1570.8 805.8 19.9
31.48 1281 1683 805.8 19.9
32.21 1407 1846.2 805.8 19.9
32.91 1554 1999.2 816 19.9
33.62 1680 2091 816 19.9
34.33 1827 2142 836.4 19.9
35.05 1995 1825.8 846.6 19.9
35.77 2079 1009.8 836.4 40.2
36.47 1995 969 795.6 38.6
37.18 1890 969 795.6 41.4
37.91 1848 1642.2 785.4 19.9
38.62 1911 2080.8 826.2 19.9
39.35 2100 1989 846.6 19.9
40.05 2184 1091.4 846.6 43.4
40.77 2184 969 805.8 39.4
41.49 2058 969 795.6 38.6
42.2 1953 1122 795.6 41.8
42.91 2100 1866.6 816 19.9
43.62 2247 2182.8 846.6 19.9
44.35 1995 969 846.6 38.6
45.07 1470 1611.6 805.8 19.9
45.78 1344 969 816 58.6
46.5 924 979.2 816 19.9
47.22 903 979.2 805.8 19.9
47.92 903 979.2 805.8 19.9
48.62 903 979.2 805.8 19.9
49.34 903 979.2 805.8 19.9
50.06 1155 1009.8 795.6 49.8
50.78 1281 1672.8 805.8 19.9
51.5 1470 1917.6 805.8 19.9
52.22 1701 2040 816 19.9
52.94 1932 1621.8 826.2 19.9
53.67 1953 969 816 39
54.38 1953 969 795.6 38.6
55.1 1659 969 795.6 57.8
55.82 1617 969 785.4 58.2
56.55 1575 1091.4 785.4 44.6
57.26 1659 1101.6 795.6 41.8
57.98 1722 999.6 785.4 58.6
58.71 1638 1244.4 795.6 37.5
59.42 1890 1764.6 816 19.9
60.12 2058 1754.4 836.4 19.9
60.86 2247 1744.2 856.8 19.9
61.58 2016 969 846.6 38.6
62.28 1449 969 816 58.6
62.98 1386 1315.8 795.6 19.9
63.7 1491 1785 805.8 19.9
64.42 1533 1132.2 816 19.9
65.14 1512 969 795.6 58.6
65.86 1218 969 795.6 58.6
66.58 924 979.2 805.8 19.9
67.3 903 979.2 805.8 19.9
68.02 903 979.2 805.8 19.9
68.74 903 979.2 805.8 19.9
69.46 903 979.2 805.8 19.9
70.18 903 979.2 795.6 19.9
70.9 903 979.2 805.8 19.9
71.62 903 979.2 805.8 19.9
72.34 903 979.2 805.8 19.9
73.06 903 979.2 805.8 19.9
73.79 903 979.2 805.8 19.9
74.5 903 979.2 805.8 19.9
75.23 903 979.2 795.6 19.9
Looking at your figures you have no boost whatsoever, you say you've checked the pipework and is OK.
Visually have you looked/watched the turbo actuator when you start the engine, it should move from the minimum to maximum boost position.
If there is no movement remove the vacuum pipe from the turbo actuator and check for vacuum while engine is idling, there is also a joint in this pipe behind the air filter you can test from here without getting under car, see pic below.
[attachimg=1]
The feed to the N75 valve is from a T piece on the large brake servo pipe just behind the fuel filter, there is also a connector that's blanked off with a cap check this is not missing.
The red arrow shows the feed to the N75 the green arrow shows what should be a blanking cap, although the photo shows a clear tube connected.
[attachimg=2]
thank you for reply
i will check that in morning but a bit of further info is my mate has the same car and his works great we noticed a difference in when i squeeze the little L shape pipe from the egr on mine it stays squeezed in when engine is revved on my mates it pressurises the pipe and returns to its coorect shape.
and your right no boost at all car doesn't reset to give boost either..
Well that would indicate you are missing the vacuum... Worth checking the reservoir is in good shape, it's the large ball shaped item at the front of the engine. I had a sharan once which had no boost and the pipe from the reservoir had sheared off as it leaves.
solved thank you to all that helped me out it was the turbo actuator that wasn't holding its pressure.
[GJ]
will it ever end
I have power now but its now got a positive boost deviation (overboost) I did make the vnt rod the same length as my old one only goes into limp mode at 60-70mph am I right in thinking I need to adjust the vnt rod??
regards as always John
Hopefully
You may need to do some more live data to see how bad it is.
Do blocks 003, 010, & 011
Make sure when your driving you get a good few seconds flat out (100% throttle) at around 3000 RPM
Thank for the reply I shall do that tomorrow as my laptop is being a pain doing updates..
regards
John
what is the best way to post the results ??
here they are thanks
[attachimg=1]
this is for better reading block 11.
Ideally like chris said you need some tidy logs 3rd gear foot down from about 2500rpm to 4000rpm. find yourself some clear road.
you have done block 005 instead of 010 so can't see whether you have 100% throttle in the 2800 to 3200 rev range or map and Maf value's
003 is showing EGR is closed when idling should be showing close to 60% or has your EGR been blanked off or disconnected.
Block 005 is showing engine temp of 60deg was the engine fully warmed up when you done test.
The boost actual reaches maximum several times that is not good.
Can you re do the log to show 003 010 011 and make sure the engine is up to temperature 90 deg
sorry did the wrong ones engine was still warming up as well i will re do it today and get back you you
thanks again
there we are and egr isn't blanked off and is clean.
[attachimg=1]
vnt rod needs to be longer to bring duty cycle down
i would expect to see <=80% at 4000rpm. If it doesnt get sorted quickly you could damage if not already your turbo.
ok thank you for the reply
make the rod longer by about 4 full turns.
MAF and MAP looks OK although EGR readings suggest diaphragm probably leaking although this wont cause your over boost.
You can only experiment with the actuator adjustment to get it back within the limits, as Redbull has already said lengthening the rod will reduce the boost.
has your car been remapped?
hi sorry for late reply have lengthened the rod and it no longer puts me in limp mode.
its not been remapped at least i think it hasn't
A little concerned about the EGR comment what do i due to remedy this or is a new egr valve?
Regards
John
Have you done a log file since to compare?
You cannot repair the EGR it's a sealed unit.
how many turns did you do?