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Discussion Starter #1
I have a Jetta that has low power like it's in limp mode. I don't have any diagnostic equipment except a Code Reader (P0102). Did a lot of "low power" trouble shooting. Still need to trace wiring and vacuum to MAF. Replaced MAF.
The things is, when I unplug the MAF sensor, the engine picks right up. Plug it back in, no power (can slowly acc. up to 50 MPH).

Tomorrow I will start tracing wiring but does this sound familiar to anyone (unplugging MAF sensor and problem goes away)?

2004 Jetta TDI 1.9 (BEW)
Tiptronic Trans
 

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If the car is as slow as a slug and it gets faster when you unplug the MAF, it's most likely a bad MAF. However, the power level will still be lower than with a good MAF. What happens is that the car substitutes a default fall back value if the signal is gone. However, when the MAF normally fails it doens't get a gone signal, it gets a low signal so the engine thinks air coming in is low.

The way to confirm this is by datalogging the MAF but if you're sure it's the MAF, a new one is cheaper than buying VCDS to datalog.
 

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Discussion Starter #3
I already replaced the MAF. That's why I'm looking at wiring today but, thanks anyway. I was just hoping soeone would have some insight as to why even a good MAF being unplugged would inprove the cars performance. Maybe I got a bad MAF (it wasn't Bosch).
 

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If you already haven't , first thing i would check is the vacuum hose going to the wastegate. I had the limp mode and thats what it was, after i replaced it, im am getting the same simptoms as you, and some kind of whooshing at acceleration. Also replaced a MAF.
 

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Discussion Starter #5
I'm thinking more and more it's a sensor issue. Due to the difference between unplugging and plugging back in the MAF sensor. If it was the wastegate, it could be the N75 solenoid. There's supposed to be another n75 solenoid somewhere in the engine that I could use to troubleshoot the WG solenoid. I'll let you know. Right now, I'm just going to order the VCSD for my car.
 

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Discussion Starter #8
VCSD Log Auto-scan

Sunday,13,March,2011,14:16:57:51709
VCDS Version: Release 10.6.3
Data version: 20101206



--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Chassis Type: 9M - VW Jetta IV
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: 3VWRR69M44M059753 Mileage: 197720km/122857miles
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Address 01: Engine Labels: 038-906-016-BEW.lbl
Part No SW: 038 906 016 H HW: 028 101 114 6
Component: R4 1.9L EDC G000AG 5375
Revision: 12345678 Serial number: VWZ7Z0C7984569
Coding: 0150034
Shop #: WSC 00066 000 00000
VCID: 19373325A91F

3 Faults Found:
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 000 - - - Intermittent
Freeze Frame:
RPM: 1008 /min
Torque: 158.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 9.88 V
Bin. Bits: 00001100
Mass Air / Rev.: 1000.0 mg/str
Mass Air / Rev.: 0.0 mg/str

16502 - Engine Coolant Temp. Sensor (G62): Signal too High
P0118 - 000 - -
Freeze Frame:
RPM: 2394 /min
Torque: 196.0 Nm
Speed: 80.0 km/h
Load: 59.2 %
Voltage: 14.06 V
Bin. Bits: 00001000
Temperature: 54.0°C
Temperature: 55.8°C

17056 - Cylinder 2 Glow Plug Circuit (Q11): Electrical Fault
P0672 - 000 - -
Freeze Frame:
RPM: 1008 /min
Torque: 84.0 Nm
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 11.02 V
Bin. Bits: 00001100
Temperature: 12.6°C
Bin. Bits: 10110000

Readiness: 1 1 0 0 1

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Address 02: Auto Trans Labels: 09A-927-750.lbl
Part No: 09A 927 750 AM
Component: AG5 Getriebe 09A 0251
VCID: 76ED18997841

1 Fault Found:
00300 - Transmission Fluid Temp. Sensor (G93)
27-10 - Implausible Signal - Intermittent

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Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 L
Component: ABS FRONT MK60 0101
Coding: 0004097
Shop #: WSC 00066 000 00000
VCID: 336BE18D2BB3

No fault code found.

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Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 1C0 909 605 F
Component: 04 AIRBAG VW61 0202 0003
Coding: 12340
Shop #: WSC 00066
VCID: 275305DDEF6B

No fault code found.

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Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J5 920 906 R
Component: KOMBI+WEGFAHRSP VDO V52
Coding: 15234
Shop #: WSC 00000
VCID: 3C79CAB106ED
3VWRR69M44M059753 VWZ7Z0C7984569

No fault code found.

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 00066
VCID: F0E1AE819A25

No fault code found.

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 1H Komfortgerát HLO 0003
Coding: 00258
Shop #: WSC 00066
VCID: 3773D59D3FCB

Part No: 1C1959801A
Component: 1H Tõrsteuer.FS KLO 0202

Part No: 1C1959802A
Component: 1H Tõrsteuer.BF KLO 0202

Part No: 1C0959811A
Component: 1H Tõrsteuer.HL KLO 0202

Part No: 1C0959812A
Component: 1H Tõrsteuer.HR KLO 0202

No fault code found.

-------------------------------------------------------------------------------
Address 56: Radio Labels: 3B7-035-1xx-56.lbl
Part No: 3B7 035 180 F
Component: RADIO 3CP 0005
Coding: 00401
Shop #: WSC 00066
VCID: 234B11CD9B53

No fault code found.

End ---------------------------------------------------------------------
 

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Discussion Starter #9
screenshots


3000+ RPMs - Graphed


3000+ RPMs


Idling.

According to DIY FAQs, this is a bad MAF (even though I replaced it w/Non-Bosch)
 

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if you still have the old MAF plug it back in and do the same logs/screen shots.

if they are the same, you have either a second bad maf, or a huge restriction in the airflow system.

how many miles on this car? have you inspected the camshaft for lobe wear? I had a car do something similiar and its camshaft was very worn out. not allowing the valves to open up. but it was reading higher values than yours..

check the torsion value on measuring block group 004 block 4 (far right one) should be somewhere between -1.0 and +1.0 0.0-+0.5 is best.

how is your boost? can you log group 001, 003, and 011 in a 3rd gear 1800-4000 rpm 100% throttle run? you have tiptronic so use that mode to keep it in a specific gear.

do the above log with the maf plugged in and also unplugged.

then post the raw unedited .csv file of the logs here? (dont know if we can attach those here or not), if not if you email it to me (growlertdi(at)gmail com) I can take a look at it for you and post a screenshot of it.
 

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Discussion Starter #12
I'm back from driving. I have to go get groceries, then I will send all the data. Thanks a bunch. One thing I noticed is that the Old MAF has even lower values than the "new." This is looking one dab MAF after another.
 

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Wow! Maybe moving the thread wasn't such a good idea.
Why not you've posted logs and graphs from VCDS and they are interesting?
 

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Because moving it seemed to have halted all the views and thread participation. But that's cool. It doesn't look like anyone is interested anyway. So I have to take it to a mechanic if the new MAF shows that the MAF is not the problem. I could change the EGR but at that point I'm just guessing. Going back to work April 5 so I will need it by then anyway. Still, I'm glad I bought the software. I just have to learn how to use it. It would be nice if Ross had a CBT software for it.
 

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Look through the section and send a PM to the guys at Ross tech for some hints. Sorry if moving it seems to have put a damper on participation, I still read your thread, just out of ideas.
 

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Because moving it seemed to have halted all the views and thread participation.
Yes this has been pointed out before as users don't know where this section is. You have to go into General Discussion then it depends if you notice it on its own at the top. I suggested a direct link on the main menu but Chitty is the boss.

I'm sorry the thread has slowed down for you? :annoyed
 
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