Quiescent current stage 1 & 2 intermittent

**rjsdavis** · 22-01-2018,03:40 AM

BTW - am presently reading this VCDS Wiki in the error code:

16618/P0234/000564 - Ross-Tech Wiki

Does anyone know where the Boost Pressure Control Valve & Boost Pressure Sensor are located on the car? Does this now need to go into a proper garage for turbo pressure output diagnostic testing?

**Rob69** · 22-01-2018,08:30 AM

The map or boost sensor will be located on the inlet pipe before the inlet manifold. IIRC and your car is similar layout to my b5 passat, the n75 is on the front (timing belt ) end of the engine next to the spherical vacuum accumulator, if not just trace back the vac hose. I suspect you have sticking vnt mechanism in the turbo. You have vcds so you can measure requested vs. Actual boost while driving, look in measuring blocks, run a log and graph it or use vcds scope to trend the data. Try a vacuum pump on the vnt actuator to check for smooth movement, At least youve sorted the knackered egr and throttle flap!

**rjsdavis** · 22-01-2018,04:48 PM

Originally Posted by Rob69

The map or boost sensor will be located on the inlet pipe before the inlet manifold. IIRC and your car is similar layout to my b5 passat, the n75 is on the front (timing belt ) end of the engine next to the spherical vacuum accumulator, if not just trace back the vac hose. I suspect you have sticking vnt mechanism in the turbo. You have vcds so you can measure requested vs. Actual boost while driving, look in measuring blocks, run a log and graph it or use vcds scope to trend the data. Try a vacuum pump on the vnt actuator to check for smooth movement, At least youve sorted the knackered egr and throttle flap!

Thank you very much Rob - very much appreciated... I hope you're right!

Excuse my ignorance, as I'm still a reasonable novice, but what's the "vnt mechanism" within the turbo? If it is this, is it a "strip and free up" type of job, or a "replace it asap" sort of job?

Also - do you happen to know how I can measure the requested -v- actual boost within VCDS (i.e. the module and which options to pick)? I'm very happy to go out and do that right now, to see if the measurements pinpoint the root problem.

**Rob69** · 22-01-2018,09:52 PM

I dont have access to my car or vcds atm, so cant tell you step by step, but i did it last year on my 1.9 passat to check my turbo and map sensor, if you google a bit or look on vcds wiki you shoul find which measuring blocks and how to log or graph. Also google or youtube vnt, loads of vids showing you the gubbins.

**rjsdavis** · 23-01-2018,02:31 AM

Right, ok... I'm learning!

So your suspicion is that the veins / control ring inside the turbo are clogged/sticking? That would seem to make sense, as I'm sure I was watching the mechanic lever up what I now believe to be the actuator (underneath the bell housing where the small vacuum pipe was attached to the top), and he didn't like how stiff that assembly was. He reckoned it should have been much freer, and his plan (next Sunday - FML!) was to disassemble this to free it up. I think we're talking about the same thing n'est pas - in that the actuator that he didn't like the restricted movement of, is actually sticky or sticking because of (potentially) a build-up of crud inside the veins/control ring inside the turbo unit itself?

Ifso, I think I understand this now... just got to work out how to use VCDS to get the turbo readings....

I just watched this video to learn from - seemed like a knowledgeable guy doing the talking:

How a VNT turbo works with diassembly and DIY repair of sticking vanes - YouTube

**Rob69** · 23-01-2018,01:05 PM

Yes, you're getting the picture. Let's know how you get on with it.

**Nard666** · 24-01-2018,05:42 PM

Originally Posted by rjsdavis

Right, ok... I'm learning!

So your suspicion is that the veins / control ring inside the turbo are clogged/sticking? That would seem to make sense, as I'm sure I was watching the mechanic lever up what I now believe to be the actuator (underneath the bell housing where the small vacuum pipe was attached to the top), and he didn't like how stiff that assembly was. He reckoned it should have been much freer, and his plan (next Sunday - FML!) was to disassemble this to free it up. I think we're talking about the same thing n'est pas - in that the actuator that he didn't like the restricted movement of, is actually sticky or sticking because of (potentially) a build-up of crud inside the veins/control ring inside the turbo unit itself?

Ifso, I think I understand this now... just got to work out how to use VCDS to get the turbo readings....

I just watched this video to learn from - seemed like a knowledgeable guy doing the talking:

How a VNT turbo works with diassembly and DIY repair of sticking vanes - YouTube

After reading your first messages since I last checked the thread (I'm no longer getting any notifications for some reason) I was thinking seems like turbo vanes (I had suspected this before but you had only mentioned underboost and although you do sometimes get underboost from what I've encountered and also what I've read overboost is more common, it may be worth mentioning any past changes in scans like that)

**rjsdavis** · 25-01-2018,01:13 AM

Okey dokey - I've finished messing around trying to extract a log of data, and think I've been at least partially successful.

Initially, I tried to bring up the measuring blocks as shown in this page: Boost check on VAGCOM (VCDS) - but VCDS wasn't really playing ball. When I entered 114 - in the top block, all of the fields just remained blank and empty. 115 worked, and brought up values etc, but I couldn't see anyway of bringing up/separating 115-3 and 115-4 - I could only bring up 115 as a three digit number and that was it. I left that and moved on.

IIRC I went into the measuring blocks section of 01 - ENGINE, and again IIRC, simply used the "TURBO" button at the top of the page to bring up prescribed measuring blocks and values. Long story short, I've logged those into an Excel spreadsheet that I will attempt to upload into this thread, although I'm not sure how, as the buttons only seem to want to insert pics and videos.

Anyway, whilst VCDS was logging the data, I took her from idle upto 3,500 RPM or so so that the values were showing the difference between requested and actual. I've just scrolled through the cells, and it's definitely showing a significantly "out of proportion" overboost, where at Specified, at about 3,000 RPM it was 1260-1280 mbars, but the actual was up at 1450-1500 mbars! I think I can see why the car is reporting an error with a clear "overboost condition".

At the moment, the car is running, and if I'm gentle, along flatish, normal roads, keeping the revs under 3,000 before a gearchange, she'll run fine (once the Overboost fault code has been cleared) - indeed, I know exactly at what point on flatish roads the overboost fault will now trigger, and VCDS can clear it live and in realtime, and the car will immediately revert back to normal driving, once the fault has been cleared until you peak the revs/turbo pressure that's requested of the engine. Clearly, whilst she can "run about" on relatively normal roads, she cannot still be used.

I tried the dual carriageway slip road (which is a fair old incline) and accelerated in third, gently - she wasn't having any of it at all and immediately went into limp mode at about 35 mph in 3rd at about 2100rpm. It's clear that more pressure is being required of the turbo to accelerate, even gently, up the incline to get up it, and accelerate up it. Therefore, it looks to me that as soon as there is sufficient difference between the specified and the actual - it's an automatic safety mechanism into limp mode, which I totally understand to protect the engine.

So.... what to make of this? I don't know if this helps to firm up the suspected diagnosis of the control ring/nozzles being gunked up and sticking as a result?

Oh, and by the way, I defo have a battery drain - discharge is sufficient to take the car from fully charged to "low battery warning" on the dash in just 48 hours. Have a charger trickle-charging the brand new battery permanently now, as I'm now pretty convinced that the drain killed the old new battery. Can't allow that to happen again, as I'll never get a second battery change under warranty!

Ok, so it won't let me upload / insert an Excel file into the forum - I'm going to do an ugly copy and paste of the log data:

Wednesday	24	January	2018	22:59:11:30461-VCID:75E15DB81CB7CBE9CA-8020	VCDS Version: Release 17.1.3 (x64)	Data version: 20170320 DS267.7
03G 906 016 MH		R4 2.0L EDC G000SG 0948

	Group A:	'003				Group B:	'011
		Engine Speed	Exhaust Gas	Exhaust Gas	Exhaust Gas		Engine Speed	Boost Pressure	Boost Pressure	Charge Pressure
	TIME	(G28)	Recirculat. (spec.)	Recirculat. (actual)	Recirc. Duty Cycle	TIME	(G28)	(specified)	(actual)	Control Duty Cycle
Marker	STAMP	/min	mg/str	mg/str	%	STAMP	/min	mbar	mbar	%
	0.13	882	295	490	99.6	0.29	882	1040.4	1009.8	78.1
	0.44	882	295	500	99.6	0.63	882	1040.4	1009.8	78.1
	0.79	882	295	490	99.6	0.94	882	1040.4	1009.8	78.1
	1.1	882	295	500	99.6	1.27	882	1040.4	1009.8	78.1
	1.43	882	295	500	99.6	1.58	882	1040.4	1009.8	78.1
	1.76	882	295	495	99.6	1.91	882	1040.4	1009.8	78.1
	2.07	882	295	495	99.6	2.23	882	1040.4	1009.8	78.1
	2.38	882	295	500	99.6	2.57	882	1040.4	1009.8	78.1
	2.73	882	295	490	99.6	2.88	882	1040.4	1009.8	78.1
	3.04	882	295	500	99.6	3.21	882	1040.4	1009.8	78.1
	3.37	882	295	495	99.6	3.52	882	1040.4	1009.8	78.1
	3.68	882	295	490	99.6	3.85	882	1040.4	1009.8	78.1
	4.01	882	295	490	99.6	4.16	882	1040.4	1009.8	78.1
	4.32	882	295	500	99.6	4.5	882	1040.4	1009.8	78.1
	4.66	882	295	485	99.6	4.82	882	1040.4	1009.8	78.1
	4.98	882	295	495	99.6	5.15	903	1081.2	1009.8	78.9
	5.31	1113	345	450	99.6	5.46	1113	1050.6	1009.8	70.2
	5.62	1008	295	525	99.2	5.8	966	1050.6	1030.2	76.9
	5.96	1134	330	470	99.6	6.12	1155	1060.8	1030.2	67.9
	6.27	1155	295	525	96.1	6.44	1155	1071	1040.4	67.1
	6.59	1218	315	525	95.3	6.76	1281	1101.6	1050.6	60.4
	6.91	1365	295	525	91.8	7.09	1365	1060.8	1071	60.4
	7.24	1365	295	540	87.5	7.4	1386	1050.6	1091.4	60.4
	7.56	1365	295	515	82.8	7.72	1407	1050.6	1101.6	60.4
	7.89	1428	295	445	77.7	8.04	1428	1050.6	1101.6	60.4
	8.2	1449	295	405	72.3	8.37	1470	1050.6	1091.4	60.4
	8.53	1491	295	360	67.6	8.68	1533	1050.6	1081.2	60.4
	8.84	1554	295	345	64.5	9	1554	1050.6	1071	60.4
	9.17	1575	295	320	62.9	9.32	1575	1050.6	1060.8	60.4
	9.48	1575	295	315	61.3	9.65	1596	1050.6	1050.6	60.4
	9.8	1596	295	300	60.5	9.95	1596	1050.6	1050.6	60.4
	10.11	1596	295	310	59	10.3	1575	1050.6	1040.4	60.4
	10.46	1575	295	300	58.2	10.62	1596	1060.8	1040.4	60.4
	10.77	1596	295	300	57.8	10.95	1617	1060.8	1040.4	60.4
	11.11	1596	295	290	57.8	11.28	1596	1050.6	1040.4	60.4
	11.44	1617	295	285	57.8	11.59	1617	1060.8	1040.4	60.4
	11.75	1596	295	300	55.5	11.91	1617	1060.8	1040.4	60.4
	12.09	1596	295	295	56.3	12.24	1596	1050.6	1040.4	60.4
	12.4	1617	295	290	57	12.56	1617	1050.6	1040.4	60.4
	12.72	1659	295	285	58.2	12.88	1680	1071	1040.4	60.4
	13.04	1659	295	290	58.2	13.19	1701	1081.2	1040.4	60.4
	13.37	1743	295	295	58.6	13.53	1722	1081.2	1040.4	60.4
	13.68	1743	295	285	58.6	13.84	1764	1101.6	1050.6	60.4
	14.01	1764	295	300	58.2	14.19	1764	1111.8	1050.6	60.4
	14.33	1764	295	305	57	14.5	1785	1101.6	1050.6	60.4
	14.66	1806	300	305	58.2	14.83	1785	1101.6	1050.6	60.4
	14.97	1806	305	300	59	15.13	1806	1111.8	1060.8	60.4
	15.3	1848	305	295	60.5	15.46	1890	1132.2	1060.8	60.4
	15.61	1848	305	305	58.6	15.77	1890	1132.2	1071	60.4
	15.95	1911	305	290	61.3	16.11	1890	1122	1071	60.4
	16.27	1932	310	305	60.5	16.46	1953	1132.2	1071	60.4
	16.61	1932	300	305	59.4	16.77	1974	1132.2	1081.2	60.4
	16.93	1953	300	310	59	17.1	1953	1122	1081.2	60.4
	17.26	1974	305	305	60.2	17.42	1953	1122	1081.2	60.4
	17.57	1974	305	310	60.2	17.74	1995	1132.2	1091.4	60.4
	17.9	1974	305	315	59.8	18.05	1995	1142.4	1091.4	60.4
	18.21	1995	305	300	60.5	18.38	1974	1142.4	1091.4	60.4
	18.54	2016	310	305	60.5	18.69	2016	1132.2	1091.4	60.4
	18.85	2016	305	320	58.6	19.02	2037	1152.6	1101.6	60.4
	19.18	2037	315	310	60.2	19.34	2016	1152.6	1101.6	60.4
	19.49	2058	315	310	60.9	19.66	2058	1162.8	1101.6	60.4
	19.82	2058	310	305	60.9	19.98	2037	1152.6	1101.6	60.4
	20.13	2058	325	310	62.1	20.31	2058	1162.8	1111.8	60.4
	20.48	2079	330	315	63.3	20.63	2058	1173	1111.8	60.4
	20.81	2058	335	310	64.1	20.96	2100	1224	1111.8	60.4
	21.12	2142	350	335	65.2	21.28	2142	1244.4	1132.2	60.4
	21.47	2121	350	340	65.6	21.63	2163	1244.4	1142.4	60.4
	21.79	2163	350	350	65.2	21.95	2163	1254.6	1152.6	60.4
	22.12	2205	355	345	66.4	22.28	2205	1275	1162.8	60.4
	22.43	2226	360	360	65.6	22.59	2247	1285.2	1173	60.4
	22.76	2310	370	355	65.2	22.92	2352	1285.2	1193.4	60
	23.07	2415	375	355	64.1	23.23	2499	1275	1213.8	56.8
	23.4	2625	400	360	64.8	23.56	2688	1275	1254.6	51.3
	23.71	2751	415	400	64.1	23.87	2793	1275	1295.4	47.7
	24.04	2814	415	420	64.1	24.2	2856	1264.8	1346.4	43.8
	24.35	2877	420	415	64.5	24.51	2898	1264.8	1387.2	40.6
	24.69	2919	420	420	64.1	24.85	2940	1264.8	1417.8	37.5
	25.01	2940	425	425	63.3	25.19	2961	1264.8	1438.2	35.1
	25.35	2961	425	420	63.3	25.51	2982	1264.8	1448.4	33.1
	25.67	2982	425	420	63.3	25.84	2982	1264.8	1458.6	32
	26	3003	425	425	62.5	26.15	3003	1264.8	1468.8	30.4
	26.3	3024	430	435	62.5	26.48	3024	1264.8	1479	29.6
	26.64	3024	430	440	64.1	26.81	3045	1264.8	1489.2	28.4
	26.97	3024	430	440	61.7	27.13	3024	1264.8	1499.4	27.6
	27.29	3024	430	425	61.7	27.44	3045	1275	1499.4	28
	27.63	3066	430	430	64.5	27.78	3066	1275	1499.4	27.6
	27.94	3066	430	455	63.7	28.12	3087	1285.2	1519.8	26
	28.28	3108	435	450	64.8	28.44	3150	1315.8	1540.2	25.3
	28.61	3171	510	500	69.9	28.77	3192	1326	1581	21.7
	28.93	3192	540	585	68.8	29.1	3192	1326	1662.6	14.2
	29.25	3213	560	560	69.9	29.43	3150	1285.2	1703.4	7.1
	29.59	2982	400	475	52.7	29.74	2730	1101.6	1621.8	54.1
	29.89	2457	330	340	27.7	30.07	2121	1040.4	1397.4	60.4
	30.22	1869	295	285	30.1	30.38	1638	1030.2	1244.4	60.4
	30.53	1407	295	295	28.5	30.71	1197	1030.2	1132.2	65.1
	30.86	966	295	350	19.5	31.02	924	1040.4	1081.2	78.5
	31.18	903	295	305	34.4	31.35	903	1040.4	1050.6	78.5
	31.5	882	295	305	34.8	31.66	882	1040.4	1030.2	78.9
	31.83	882	295	290	41	32	882	1040.4	1020	78.9
	32.16	882	295	290	41	32.32	861	1050.6	1009.8	78.9
	32.49	882	295	285	42.2	32.64	882	1050.6	1009.8	78.9
	32.8	861	295	285	44.1	32.96	882	1050.6	999.6	78.9
	33.13	882	295	285	44.5	33.29	882	1050.6	999.6	78.9
	33.44	882	295	280	46.1	33.6	861	1050.6	999.6	78.9
	33.77	882	295	295	46.1	33.93	882	1050.6	999.6	78.9
	34.08	882	295	290	47.3	34.24	882	1050.6	999.6	78.9
	34.41	882	295	290	46.1	34.57	882	1050.6	999.6	78.9
	34.73	882	295	285	47.3	34.92	882	1040.4	999.6	78.9
	35.08	882	295	290	47.3	35.24	882	1050.6	999.6	78.9
	35.39	882	295	285	49.6	35.56	882	1050.6	999.6	78.9
	35.72	882	295	295	48	35.88	882	1050.6	999.6	78.9
	36.04	882	295	275	51.6	36.21	882	1050.6	999.6	78.9
	36.37	882	295	275	53.1	36.53	882	1050.6	999.6	78.9
	36.68	882	295	295	49.6	36.85	882	1040.4	999.6	78.9
	37.01	882	295	290	48.4	37.16	882	1040.4	999.6	78.9
	37.32	882	295	290	48.4	37.51	882	1040.4	999.6	78.9
	37.67	882	295	290	50.4	37.82	882	1040.4	999.6	78.9
	37.98	882	295	300	49.2	38.15	882	1050.6	999.6	78.9
	38.31	882	295	300	48	38.46	882	1040.4	999.6	78.9
	38.62	882	295	290	50.4	38.79	882	1050.6	999.6	78.9
	38.95	882	295	285	50.8	39.1	882	1040.4	999.6	78.9
	39.26	882	295	305	48.4	39.43	882	1040.4	999.6	78.9
	39.59	882	295	295	48.4	39.74	882	1040.4	999.6	78.9
	39.9	882	295	290	48.8	40.08	882	1040.4	999.6	78.9
	40.24	882	295	285	50	40.4	882	1040.4	999.6	78.9
	40.56	882	295	280	50	40.73	882	1040.4	999.6	78.9
	40.89	882	295	285	50.4	41.04	882	1050.6	999.6	78.9

**Rob69** · 25-01-2018,08:24 AM

If you watch the turbo actuator rod as the engine is started you should see it travel to the limit stop to close the vanes and allow max boost when required, as engine load increases the n75 solenoid bleeds actuator vacuum to open the vanes and limit boost, you seem to have sticking mechanism, n75 solenoid fault or map sensor reading boost pressure incorrectly. If you had a faulty map sensor or n75 i would expect to see an error code for it or the offset between requested and actual to be there from the start rather than opening up as boost increases. I cant see your actual boost in the vcds log but am presuming requested and actual deviation increases as boost increases rather than the offset being there from the start. I'm no expert but do suspect the vnt is sticking. Sorry- got no idea where your current drain is going, vcds might indicate which module is remaing active or pulling fuses to certain items might show up on an ammeter in line with the battery, i've had the alarm siren internal battery fail, and do strange things to my alarm system, and they always seem to fail after several years.

**rjsdavis** · 25-01-2018,03:03 PM

Originally Posted by Rob69

If you watch the turbo actuator rod as the engine is started you should see it travel to the limit stop to close the vanes and allow max boost when required, as engine load increases the n75 solenoid bleeds actuator vacuum to open the vanes and limit boost, you seem to have sticking mechanism, n75 solenoid fault or map sensor reading boost pressure incorrectly. If you had a faulty map sensor or n75 i would expect to see an error code for it or the offset between requested and actual to be there from the start rather than opening up as boost increases. I cant see your actual boost in the vcds log but am presuming requested and actual deviation increases as boost increases rather than the offset being there from the start. I'm no expert but do suspect the vnt is sticking. Sorry- got no idea where your current drain is going, vcds might indicate which module is remaing active or pulling fuses to certain items might show up on an ammeter in line with the battery, i've had the alarm siren internal battery fail, and do strange things to my alarm system, and they always seem to fail after several years.

Hello Rob

Thank you for that post - it all looks logical to me, and I'm unable to find anything that doesn't make sense to me.

Can you not see the boost figures? There's a large table at the bottom of my last post, and they're all in there. Engine speed is the fourth column from the right, Specified Boost is the third from the right, Actual Boost is the second from the right. As you can see from the three columns, as the engine speed gets upto about 2800RPM, the specified and actual are largely in line with one another, but the actual then starts racing ever further away from the specified from about 2800-2900RPM onwards and just gets worse as the engine speed increases...