Sarts and dies only when hot G28/G40 fault

Lazzar2010

Member
Joined
Dec 12, 2015
Location
Hawaii
TDI
2010 Jetta Sport Wagon DGS
Simply car runs great starts with 1 or 2 cranks when cold but will start and immediately die when warmed up. If I let it cool with hood up for about 2 hours starts as usual.

In hunting for the fault caused by heat I found cooling the Throttle Body down with ice water would allow the car to start in minutes. So it would seem it is going bad and the increased heat causes the resistance to go out of specs or cooling it is sending a false reading to the ECU.

This has been going for over a year and about 30k with no change.





VCDS Mobile 0.4231.0.4

VIN: 3VWTL7AJ3AM664793

Chassis Type:5K or AJ
Scan: 01 02 03 08 09 0F 10 13 14 15 16 17 18 19 1C 22 25 2E 37
42 44 47 4F 52 55 56 5F 62 65 69 72 77

VIN: 3VWTL7AJ3AM664793




-----------------------------------------------------------------
Address 01: Engine Labels: 03L-906-022-CBE.clb
Part No SW: 03L 906 019 CM HW: 03L906022TS
Component: R4 2,0L EDC G000AG 7967
Revision: 12H03--- Serial Number:
Coding: 0050078
Shop #: WSC 22601 444 101434
VCID: 78B37BE35DB75B908E62234-802D

1 Fault Found:
000022 - Bank 1: CMP Sensor (G40) / Engine Speed Sensor (G28)
P0016 - 000 - Incorrect Correlation - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 2
Fault Frequency: 92
Mileage: 178358 km
Time Indication: 0
Date: 2010.14.17
Time: 13:58:33
RPM: 1265 /min
Speed: 0.0 km/h
Voltage: 11.86 V
Temperature: 93.6°C
RPM: 559 /min
(no units): 33.0
 

Hydro3

Well-known member
Joined
May 15, 2013
Location
Toronto, ON
TDI
2010 Golf TDI
I had this exact same problem on my 2010 Golf. I ended up replacing the cam position sensor and that solved the issue.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
Cooling throttle body with water? Uhm, sorry what..?

Camshaft position sensor is not that important. It is impossible to start with it malfunctioning.
However, it won't start with fault crankshaft sensor.

Once the car refuses to start, hook up vcds and find measuring values for both sensors - cam and crank. Turn the key to Start position to start cranking. Observe the RPM. Crankshaft sensor should be showing 220-280 RPM, cam sensor half of that. Notice the sensor which has got bad reading. This will be the sensor you need to replace.
 

Lazzar2010

Member
Joined
Dec 12, 2015
Location
Hawaii
TDI
2010 Jetta Sport Wagon DGS
Thank you for the info. I am not sure what the part is called on a TDI but it is after the intercooler and right before the the EGR and intake manafold. It looks like a throttle body. All I know is if I cool it down the car starts. I will do the test you suggested just need to find them in the software.
 

Lazzar2010

Member
Joined
Dec 12, 2015
Location
Hawaii
TDI
2010 Jetta Sport Wagon DGS
So cycling the throttle body module in output test seams to allow the car to start so it seems to be a problem with it and not the sensors.
 

Henrick

Top Post Dawg
Joined
Aug 24, 2010
Location
Ireland
TDI
Golf VI TDI, 77 kW (CAYC)
It's ASV, anti shudder valve. It must be open in order for a car to be able to start.
Looks like yours might have damaged internals. Most likely you will need to replace it.
 

Lazzar2010

Member
Joined
Dec 12, 2015
Location
Hawaii
TDI
2010 Jetta Sport Wagon DGS
OK great thank you so much for your help. Funny though the Rosstech app ID'S it as a throttle boddy. I will check it when it is hot to see if it is open on start. I guess cooling it is some how changing resistance in drive motor. Odd though your would think it would give me some kind of fault code.
 

Lazzar2010

Member
Joined
Dec 12, 2015
Location
Hawaii
TDI
2010 Jetta Sport Wagon DGS
Well it is open so much for that. Is assume there may be a half effects sensor in the unit that is not sending correct signal to ECM. Coolong it down with water works every time and it takes only about a gallon of water poured slowly over it to work. Rest of engine only cools a few degrees in that time. Sure is a weird one? Also the manifold flap seems to be working correctly as well.
 
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