Limp Mode after Warm Up

2002 Jetta, 445K miles. At first start from an overnight, the car will appear to boost fine, it accelerates normally. As the car warms as it is driven, the boost seems to decrease (no boost gauge, yet) until the car cannot go up slight grades on interstates without losing speed. It has a new N239 valve and new turbo actuator. The actuator goes through the entire motion from about 3mmHg to 17mmHG. I have looked at it from below and with a mirror cold and hot.

I tried to manually boost using my mightyvac, but at zero and at 17 nothing changed and the car did not accelerate well. The full version VCDS scan is below.

Monday,01,July,2019,18:39:44:23395
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 19.6.0.2 (x64)
Data version: 20190529 DS308.0
www.Ross-Tech.com


VIN: 3VWSP69M42M011724 License Plate:


Chassis Type: 9M (9M - VW Jetta IV (1998 > 2014))
Scan: 01 02 03 08 09 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57
75 76

VIN: 3VWSP69M42M011724
-------------------------------------------------------------------------------
Address 01: Engine Labels: 038-906-012-AGR.clb
Part No: 038 906 012 FD
Component: 1,9l R4 EDC G000SG 4102
Coding: 00002
Shop #: WSC 00066
VCID: 57B774EAB55607F780-4B00
3VWSP69M42M011724 VWZ7Z0A3842382

2 Faults Found:
19561 - Valve for Intake Manifold Flap (N239)
P3105 - 35-10 - Open or Short to Ground - Intermittent
17964 - Charge Pressure Control
P1556 - 35-10 - Negative Deviation - Intermittent
Readiness: 1 1 0 0 0

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 C
Component: ABS FRONT MK60 0103
Coding: 0004097
Shop #: WSC 00066 000 00000
VCID: 2A51FD1E86A44A1FEF-513C

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 6Q0 909 605 F
Component: 04 AIRBAG VW6 0202 0004
Coding: 12340
Shop #: WSC 00066
VCID: 3A71CD5E2604FA9F9F-5102

No fault code found.

-------------------------------------------------------------------------------
Address 16: Steering wheel Labels: 1J0-907-487-A.lbl
Part No: 1J0 907 487 B
Component: Lenkradelektronik 0002
Coding: 00008
Shop #: WSC 00066
VCID: 3065EF76F07830CF21-51B2

No fault code found.

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J0 920 906 L
Component: KOMBI+WEGFAHRSP VDO V07
Coding: 07232
Shop #: WSC 09519
VCID: 3163EA72FB7239C72E-5102
3VWSP69M42M011724 VWZ7Z0A3842382

1 Fault Found:
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.lbl
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 00000
VCID: 70E52F7630F870CF61-5102

1 Fault Found:
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
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: 3777D46A1516E7F760-4AE6

Subsystem 1 - Part No: 1C1959801A
Component: 1H Tõrsteuer.FS KLO 0002

Subsystem 2 - Part No: 1C1959802A
Component: 1H Tõrsteuer.BF KLO 0002

Subsystem 3 - Part No: 1C0959811A
Component: 1H Tõrsteuer.HL KLO 0002

Subsystem 4 - Part No: 1C0959812A
Component: 1H Tõrsteuer.HR KLO 0002

1 Fault Found:
00935 - Electric Window Motor; Rear Right (V27)
35-10 - - - Intermittent

End-------------------------(Elapsed Time: 05:26)--------------------------


Suggestions?

Doug

I suggest you read Canadian_Grizzly's Limp Mode thread and proceed accordingly.

If this began after you installed a new actuator, or you installed a new actuator since it started, the actuator is out of assessment.
I keep reading the 3mbar to 17mbar and knowing it's wrong unless installed on a table.
You have VagCom and should do some body logging then adjust it to where it needs to be.
The actuator moves between the stated vacuums, however, the turbo must have the correct movement also.
I would log and then do 5 turns taking pressure off with a vacuum pump until it's boosting correctly. Usually it's going fast enough to overboost, then turn it back a little.

Sent from my Armor_2 using Tapatalk

The solution to this problem seems to be across many issues, the car does have 450k miles on the engine and 250k on the turbo. The vacuum check valve was non-functional and was replaced. The VNT actuator diaphragm had a leak and the actuator was replaced with new. The N75 valve was not functioning properly and was replaced with new. The horn fuse was found to be bad, and replaced with new. And the brake switch was replaced with new just because it is cheap and easy. After doing all of this, the issue would still occasionally popup, but always after the vehicle had been driven for 10-12 miles. I found a spare N75 valve in my remnants stash from a B5 1.8T (same part number) and replaced it, just because. The car has been driven over 220 miles now without recurrence of limp mode. Hopefully, this puts this issue to bed.

If it's working don't try to fix it.

While you had the actuator off did you move the lever going into the turbo by hand full travel?
Should have been free & smooth.