Fault code P0238 MAP sensor

[Mecksopp]

Hi,

I have a problem with my Superb tdi 2.0 140hp 4x4 alldrive, 2013 (current 120000km).

Flashing coil lamp during drive, car switched to limp mode.

After ignition on/off the car can work ok for a longer or shorter period.

Engine lamp will be turned on after a while.

Reading error codes gives intermittent fault P0238.

The local store did not have sensor home but I found a used one (the dealer says it is tested and ok...).

Installed the new one but same problem.

So now I am wondering if I have two faulty sensor or a cable problem to the sensor or any other serious problem.

 

To verify the sensor and cable I need the specification or at least the pin layout on the sensor, I can not find either when searching on the web.

Would be great if someone have this information or any other idea?

 

The original sensor part number is:

0 281 002 977

03G 906 051E

 

BR

Edited 29 July, 2019 by Mecksopp

[3T51704x4]

Look at the MVB for word 01 and find the actual and specified boost for the thrust sensor, then compare with the ambient pressure reading of the engine ecu, should be very similar with the engine off, ignition on. You more than likely have a broken wire within the PVC which may look OK.

 Will get my CFD out later to confirm. Should look similar to this although yours is an E, the wiring will be the same. This is a test lead I knocked up to do inline tests.

NB don't take any notice of the colours I used for the test lead.

 

Edited 30 July, 2019 by 3T51704x4

[3T51704x4]

This info is current for my VIN, NOV 2011 on

G31 - Charge Pressure Sensor (parts call it a thrust sensor)

G42 Intake air temp sensor in same housing as G31

J623 - Engine ECU old school word 01 new school address 01

T94a- 94 pin connector on engine ecu

T4bl- Black four pin connector somewhere on or around the gearbox. 

All wires are 0.5mm

Pin 1 of G42 is brown which goes to terminal 1 of the T4bl connector then to T94a/66 which means pin 66 of the 94 pin connector.

Pin 2 of G42 is yellow which goes to terminal 2 of T4bl then changes to red/green out of T4bl (still pin 2) to T94a/30 (pin 30).

Pin 3 of G31 grey/black to pin 3 T4bl to pin 17 T94a

Pin 4  of G31 purple to pin 4 T4bl to pin 83 T94a

 

So:

Pin 3 5V in to sensor for both G31 and G42 via engine ecu

Pin 1 Earth for both sensors via engine ecu

Pin 2 variable signal back to engine ecu for G42

Pin 4 variable signal back to engine ecu for G31

If you plugged in a known good sensor, the fault must be either wiring or much less likely, the engine ecu.

Edited 30 July, 2019 by 3T51704x4

[Mecksopp]

Thank you for the information!  😀

We had a planned vacation trip so I am now off with the family in our Skoda Rapid. Not much space left compared to the Superb 😀

 

Before I left I drove the Superb to a repair garage, besides the sensor wiring he suspected the turbo actuator, could that be the case?

We will see what findings he have done when we get home.

 

I repaired the wirings to driver door last year so I would not be surprised if it is a wiring problem. Seems that the PVC is not of the best quality.

If there is a wiring problem it should must likely be near the sensor or?

(in all other places the wiring seems to sit tight)

 

[3T51704x4]

The actuator on the turbo can fail, but it would normally give an underboost fault rather than a specific G31 issue.

The rubber diaphragm fails so easy test with vacuum tester like mityvac tester. If they can’t pull vacuum, it has failed, the wiring can also fail to that as well as the vacuum pipes being chewed through via rodents. 

You just need someone who is familiar with the product to get a first time fix.

Should be quite straight forward for any competent tech to solve.

[Tech1e]

20 minutes ago, 3T51704x4 said:

the wiring can also fail to that as well as the vacuum pipes being chewed through via rodents. 

 

Beech Marten!!

[Tech1e]

VW were plagued with wiring issues with the boost sensor a number of years ago. They did release a wiring harness overlay for the TDI to rewire the sensor back to the ECU,

[3T51704x4]

I remember they did a loom kit for the boost sensor on the Passat, will have a shufty through hst at lunch to see if I can find a part number

[3T51704x4]

I have a VAS 1978 kit so could easily make one if not.

[Tech1e]

3 minutes ago, 3T51704x4 said:

I have a VAS 1978 kit so could easily make one if not.

 

I was the only one that ever used ours, everyone else was scared.

[3T51704x4]

Ha, best tool in my view. Love using it

[3T51704x4]

Found the TPi last updated in 2015. (But the info was avail back around 2011)

Edited 31 July, 2019 by 3T51704x4

[3T51704x4]

[Tech1e]

Plucked that one out of obscurity that’s for sure. 

[3T51704x4]

@Tech1e

You reminded me I had seen a bulletin for the boost sensor, just had to try and find it.

At least if the garage fit the kit, you know it will be sorted once and for all.

Edited 31 July, 2019 by 3T51704x4

[Mecksopp]

Thanks for all info.

I get back with info how it goes.

BR

[Mecksopp]

Hi again!
Today I picked up the car, now everything is working.

The problem was the wire for:

Pin 4 variable signal back to engine ecu for G31

 

The first repair garage could not fix the problem, they where first sure that it is was the air pressure sensor and changed that one.

I had to pay approx 2300SEK to them for the sensor and work,  then they tranfered the car to an authorized Skoda repair garage, they fixed the wire for approx 4500SEK.

Total cost for me approx 6300SEK...

 

I have asked for where the wire was broken (if it was near the sensor or closer to the ECU), have not got any answer on that yet.

According to the work spec it seems that they have repaired the wire, i.e not replaced the complete wire.

 

I wish I would have had the time to do the fault finding myself, no problem for me to do some soldering of a wire. Had a lot of problem with the wiring to driver door before which I fixed myself.

Thinking of buying a fault code reader, what to you suggest?

 

Anyway, thank you for your help.

BR

[3T51704x4]

Glad it is fixed now, not sure how much that is in GBP, but sounds a lot. In future I would take your car to the main agent as it sounds like you paid the first garage for something they weren’t able to fix, don’t take it back to them again. Did they refund you?

Soldering is not used at the main dealer if done properly as it attracts moisture and can have a higher contact resistance than a correctly crimped ferrule.

The ferrules the dealer use are then heated to seal the joint to prevent moisture ingress which is why you get black wire corrosion.

Never poke a probe into a wire, if you must, make sure you seal the hole.

[Mecksopp]

6300SEK is about 545GBP.

No refund from the first garage.

Thanks for the probe tips.

Do you have any opinion about which fault code reader system I should buy?

 

[Tech1e]

Look into Carista

[3T51704x4]

I have no experience with generic scanners so I would not be the one to ask, sorry.

 

 I use a genuine VAS 6150 linked to a genuine VAS 5054 with factory ODIS service.

I have a hookie version of ODIS engineering I needed to retrofit rear LED tail lights (thanks Langers2k) and a genuine Hex Net unlimited VIN VCDS unit from Ross Tech purchased from Gendan, again for various coding of ECUs as the factory service version won’t allow changing certain codes.

 

Edited 13 August, 2019 by 3T51704x4

[3T51704x4]

51 minutes ago, Mecksopp said:

6300SEK is about 545GBP.

No refund from the first garage.

That is outrageous, they fitted an unnecessary part which failed to fix the problem and charged you for the pleasure???

This makes me fume, people who have no clue, charging top money to fit parts which may work.

May as well play lucky dip at TPS. Gerrrrr

 

The repair wire would have been around £4, and the sealable ferrule £6!!!!!!

and someone who knows what they are doing around 30 mins to carry out the repair and possibly 1 hour to track the fault down with the correct tools.

Edited 13 August, 2019 by 3T51704x4

[Mecksopp]

Hi!

I got some answers.

They worked according to TPI 2027092/3.

(sorry for swedish)

* TAGIT FELMINNE FELKOD FINNS

* KOLLAT TPI HITTADE ETT SOM STÄMMER PÅ KUNDENS BESKRIVNING

* FÖLJT TPI KONTROLPUNKTER

* PROVAT ATT BYTA G31 BLEV INGE BÄTTRE

* GJORT GUIDAD FELSÖKNING FEL

* KOLLAT TURBON OK

* MÄTT TRYCKET I LADDRÖRET DET STÄMMER

* MÄTT STRÖMMEN TILL G31 FRÅN MOTORSTYRDORNET DEN STÄMMER

* MÄTT JORDEN FRÅN MOTORSTYRDORNET DEN STÄMMER

* MÄTT SIGNALKABEL FRÅN MOTORSTYRDORNET FEL MOTSTÅND I KABELN

* LETAT FELET PÅ SIGNALKABELN HITTADE ETT BROTT PÅ DEN I KABELSTAMMEN

* LAGADE KABELBROTTET PROVKÖRDE BILEN DEN FUNGERADE SOM DEN SKULLE

* TAGIT FELMINNE FINNS INGET KVAR

 

The replaced 30 cm of the cable close to the map sensor.

 

[3T51704x4]

* TAGIT MISCELLANEOUS ERROR CODE FOUND
* CHECKED TPI FINDING A CONFIRMATION OF CUSTOMER DESCRIPTION
* FOLLOWED TPI CHECK POINTS
* TRY TO REPLACE G31 WAS NO BETTER
* MADE GUIDED TROUBLESHOOTING ERRORS
* CHECK OUT TURBO OK
* MEASURE THE PRESSURE IN THE CHARGING TUBE IT'S CORRECT
* MEASURING THE POWER TO G31 FROM THE ENGINE CONTROL THAT IS CORRECT
* MEASURE THE EARTH FROM THE ENGINE CONTROL IT IS CORRECT
* MEASURED SIGNAL CABLE FROM MOTOR CONTROL TORN ERROR RESISTANCE IN CABLE
* MISSED THE SIGNAL CABLE ERROR FOUND A BREAK ON IT IN THE CABLE TUBE
* REPAIRED CABLET TRIAL THE CAR WORKED AS IT WOULD
* TAKING THE ERROR MEMORY AWAY.

[3T51704x4]

Least the dealer tech knows what to do, expensive repair though.

Would have been cheaper for you to pay my return flight and fix it for you.