Turbo cuts out, error code P0652

Hey gang.



I have a 2005 Golf TDI. It ran great until midwinter when the turbo started dropping out when the weather was very wet. When the weather dries up a few days it returns to normal.


VCDS reports the following:


Chassis Type: 1J (1J - VW Golf/Bora IV (1998 > 2006))
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: x Mileage: 267670km-166322miles
-------------------------------------------------------------------------------
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 G000SG 6327
Revision: 12345678 Serial number: XXXXXXXXXXXXXX
Coding: 0150031
Shop #: WSC 66565 257 00032
VCID: 193705CAD3F8A78740-515A

1 Fault Found:
17036 - Sensor Reference Voltage B
P0652 - 000 - Voltage too Low - Intermittent
Freeze Frame:
RPM: 2058 /min
Torque: 78.0 Nm
Speed: 0.0 km/h
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000
Bin. Bits: 00100000

Readiness: 0 1 0 0 0


I snooped around looking for causes and it seems like it could be any of numbers of faults - MAP sensor, MAF, sensor, wiring, ECU, turbo actuator. But I think the big clue is the weather component.



Additional notes about the car:
1. I swapped the turbo and exhaust manifold for a VNT-15 two years ago.

2. ECU has a Malone stage 1 tune
3. PD150 intake
4. Converted to manual gearbox from autotragic



I have no idea where to start. How do I further diagnose the fault?


Thanks!

I'd look at the wires and connectors. Also look in the air filter box next time it rains.

Did you check: http://wiki.ross-tech.com/wiki/index.php/17036/P0652/001618
Could be a wire problem as mentioned.

Hi there,


Yes, I saw the entry. Thank you for drawing attention to that.


Today I removed the MAP sensor and cut off the plug. The wires from the sensor back along the tiny 24awg wires were halfway corroded almost four inches from the connector. Not terrible but certainly invisible since the wire shielding looked fine.


I spliced in a brand new connector I obtained from the dealer for $13 and installed a new MAP sensor just for fun. The tools I have to disconnect the terminals inside the connector didn't work so I ended buying a pair of yellow wires with terminals on both ends - for $50. Ouch. But if it solves the problem then it's easily worth the money.



Went out for a long spin tonight and it ran great, but today was very cold and dry so I didn't expect any trouble. When the rain comes back in a few days we'll see how it behaves.


Thank you for the responses.

Location: Portland

Portland what?
Just want to say 'if you are running w/o belly shield and side skirts corrosion problems
are likely to continue! Especially if you're in Portland ME!
EDIT: stuff like your turbo actuator won't get hot enough to dry out if your shields are missing.

Oh - Portland, Oregon. It's a town with a lot of rain. If you down enough antidepressants and Vitamin D the rain becomes liquid sunshine.

I installed a nice bottom shield a couple of years ago when I put this car together. But for its previous 140,000 miles it didn't have one.

My thought is that the actuator is only two years old so I doubt it would fail this quickly. I guess we'll find out.

Well, no luck. We had rain last and predictably I have no boost today. The CEL is throwing the same error. I had hoped the new connector and sensor would have solved the issue. Ah well. What should I do next?

i just did a search for "P0652 wet"
may be your computer. and perhaps get a live data grab for us next time you are out for a rainy weather drive.





https://www.ford-trucks.com/forums/1076579-2008-6-4l-with-codes-high-idle-and-dead-pedal.html


https://www.ford-trucks.com/forums/1278643-loss-of-acceleration-question.html

update

So a friend came by this evening to help me do some troubleshooting. Here's what we have:


1. We checked the vacuum connections with a Mityvac and the turbo actuator holds vacuum and actuates the rod.


2. We pulled the vacuum check valve near the N75 valve and it correctly works one way.



3. We bypassed the N75 valve with just using the N18 valve. No boost.


4. Disconnected the connector on the turbo actuator and I get boost - not full boost, but certainly some. I don't know what the means or how to continue.


The Ross-Tech wiki says to do the following:


"Check Atmospheric Pressure (MVB 010.2) and Intake Manifold Pressure Sensor (MVB 010.3). Compare both Values with Engine OFF, the Tolerance should be +/- 50 mbar."


Great - but how do I do that exactly? With VCDS? I don't understand.

I have to say I'm confused also.
There's 2 air pressure sensors ?

Do you see the 2 readings in VCDS and are they about the same with the engine not running?

When you changed the MAP sensor plug was there any sign that 2 wires may have touched?

wonneber said:

I have to say I'm confused also.
There's 2 air pressure sensors ?

Do you see the 2 readings in VCDS and are they about the same with the engine not running?

When you changed the MAP sensor plug was there any sign that 2 wires may have touched?

Click to expand...

Hi. Thanks for replying.

I don't see the readings in VCDS because I don't know where to look for them or what the procedure is. I have VCDS but no expertise. In the past I've only used it to runs scans to find and clear CEL codes.

I've searched around but all I see is the same copy / paste that I included above from Ross-Tech. I get that I'm supposed to do an atmospheric pressure test but I simply don't understand how to do that.