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#1 · Mar 12, 2019 Hi all, whilst trying to figure out the reason for my golf going into limp mode when reaching 3.5k revs, I believe I've narrowed it down to either a bad or poorly-earthed MAP sensor or sticky turbo vanes. Whilst trying to locate the MAP sensor I noticed this little fella has been snapped off for some time. It's still connected and appears to be some sort of sensor/ temp gauge. Any clues out there? Also, can anybody help direct me to where the MAP sensor is on a 2005 Golf Mk5 2.0 TDI and, even better, a wiring diagram? Thanks

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See less See more 1 Sort by Oldest first Oldest first Newest first Most reactions #2 · Mar 12, 2019 Ambient temperature sensor. #3 · Mar 12, 2019 If you can tell me the engine code and year of the car, I may be able to find wiring info. Engine code is on the data sticker on boot floor. #4 · Mar 12, 2019 Hi Pete1, thanks for the help. Here is the engine code. Also, I connected an OBD2 reader which threw up the code P0234 Engine Overboost Condition, which is what I'm trying to get to the bottom of. When going above 3.5k the engine is going into limp mode. The manifold pressure reading got stuck at around 100 and wouldn't drop down at this point. From researching the internet I can see quite a few turbo-related issues on the BKD engine, either stuck vanes or MAP issues. Do you have any knowledge of this? Thanks again

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0 Reply #5 · Mar 12, 2019 In the vast majority of cases, with any VAG TDI engine that code will be a clogged and worn turbo but in the case of a BKD it is almost certainly a turbo fault, I had two in today with it..... a VERY common problem with this model. #6 · Mar 13, 2019 Hey Crasher thanks for that. If the OBD2 reading is showing that the manifold pressure is not dropping once the fault occurs after 3-4k revs, could it be a blocked actuator/ waste gate issue? My knowledge is basic in this area but I can cause the limp mode pretty much on demand by revving hard to this point and it's as though the power just stops. It can be reset by turning the ignition off and on again and won't happen until it reaches the same rev range. Or in your experience do you think it's a new/ recon turbo solution? thanks again 0 Reply #7 · Mar 13, 2019 Once, many years ago (2003 ish) I had a just out of warranty A4 1.9 TDI 130 (AVF engine) in for a limp home problem which would reset each time the ignition was cycled and the Audi dealer was quoting silly money for a new turbo. This was in the early days of the PD TDI staring to cause problems and we were having a lot of turbo’s sticking. I noticed the boost pressure reading was going upto 2880mBar (it’s maximum reading) and would stick there, then reset once the ignition had been cycled. I generated the fault on a road test and left it running, went into the engine bay and tapped the “Thrust” sensor (really easy to get at on these) and the reading dropped back to atmospheric. A new sensor cured it but I have never seen this fault since. #8 · Mar 13, 2019 First posts normally go in introductions else you could get a free fix and we never see you again!!! As said that is Ambient (Outside) Air Temperature Sensor (G17) VAG Error Code: 16618/000564 EOBD II Error Code: P0234 Fault Location: Boost Pressure Regulation - Limit Exceeded (Overboost Condition) Possible Cause: Malfunction Indicator Lamp (MIL)(K83) active. Boost Pressure too high. Reduced Power Output. Hoses incorrectly connected, disconnected, blocked or leaking. Solenoid Valve for Boost Pressure Control (N75) faulty. Manifold Pressure/Boost Sensor (G31) faulty. Turbocharger stuck/faulty. Exhaust Gas Recirculation (EGR) Valve blocked. Possible Solutions: Check Charge Pressure Control System. Read Measuring Value Blocks (MVB). Perform Output Test (to check the Turbocharger). Perform Basic Setting (to check the Charge Pressure Control). Difference of set value boost pressure vs. altitude sensor signal > 200 - 1275 hPa. Perform Pressure Test to locate Leaks. Check/Replace Solenoid Valve for Boost Pressure Control (N75). Check/Replace Manifold Pressure/Boost Sensor (G31). Check/Replace Turbocharger. Check and clean Exhaust Gas Recirculation (EGR) Valve. Description: The boost pressure sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position and engine speed. The Engine Control Module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost pressure sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The Engine Control Module (ECM) supplies 5 volts to the boost pressure sensor on the 5-volt reference 2 circuit, and provides a ground on a low reference circuit. The boost pressure sensor provides a signal to the Engine Control Module (ECM) on a signal circuit relative to the pressure changes. The Engine Control Module (ECM) monitors the boost pressure sensor signal for voltage outside of the normal range. The Engine Control Module (ECM) calculates a predicted value for the boost pressure sensor. The Engine Control Module (ECM) then compares the predicted value to the actual signal. As taken from my new EOBD II Fault Codes Software #9 · Mar 13, 2019

Keithuk said: First posts normally go in introductions else you could get a free fix and we never see you again!!! As said that is Ambient (Outside) Air Temperature Sensor (G17) VAG Error Code: 16618/000564 EOBD II Error Code: P0234 Fault Location: Boost Pressure Regulation - Limit Exceeded (Overboost Condition) Possible Cause: Malfunction Indicator Lamp (MIL)(K83) active. Boost Pressure too high. Reduced Power Output. Hoses incorrectly connected, disconnected, blocked or leaking. Solenoid Valve for Boost Pressure Control (N75) faulty. Manifold Pressure/Boost Sensor (G31) faulty. Turbocharger stuck/faulty. Exhaust Gas Recirculation (EGR) Valve blocked. Possible Solutions: Check Charge Pressure Control System. Read Measuring Value Blocks (MVB). Perform Output Test (to check the Turbocharger). Perform Basic Setting (to check the Charge Pressure Control). Difference of set value boost pressure vs. altitude sensor signal > 200 - 1275 hPa. Perform Pressure Test to locate Leaks. Check/Replace Solenoid Valve for Boost Pressure Control (N75). Check/Replace Manifold Pressure/Boost Sensor (G31). Check/Replace Turbocharger. Check and clean Exhaust Gas Recirculation (EGR) Valve. Description: The boost pressure sensor responds to pressure changes in the intake manifold. This pressure is created by the turbocharger and changes with accelerator pedal position and engine speed. The Engine Control Module (ECM) uses this information to assist in diagnosis of the barometric pressure (BARO) sensor and to provide engine overboost protection. The boost pressure sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The Engine Control Module (ECM) supplies 5 volts to the boost pressure sensor on the 5-volt reference 2 circuit, and provides a ground on a low reference circuit. The boost pressure sensor provides a signal to the Engine Control Module (ECM) on a signal circuit relative to the pressure changes. The Engine Control Module (ECM) monitors the boost pressure sensor signal for voltage outside of the normal range. The Engine Control Module (ECM) calculates a predicted value for the boost pressure sensor. The Engine Control Module (ECM) then compares the predicted value to the actual signal. As taken from my new EOBD II Fault Codes Software Click to expand...

Apologies for misplacing the post and thanks for the information. I have heard that it's possible to rule out faulty solenoids by switching them over so would it make sense to do N75 with another one, I assume the G31? My best guess is that the actuator lever/ arm is sticking and/ or the vanes/ control plate as the pressure is building but not releasing. It may also be faulty/ corroded wiring on the MAP sensor so the ECU believes there's too much pressure and puts engine into limp mode? I need some time to get in there and rule things out one by one. Or pay a local mechanic to do this now that I'm armed with your helpful info. 0 Reply #10 · Mar 13, 2019 G31 is a sensor, not an actuator, so you can't swap it for an actuator (solenoid). #11 · Mar 13, 2019 Ah ok Pete1, not sure which one's the post I read must have been talking about then. Thank you though This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread. Insert Quotes Post Reply

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