N75 Valve

[waynepixel]

Hi

Quick question, could someone here explain to me why VAG COM did not pick up on a faulty N75 valve when my car had a boost problem last year. Does this kind of valve have to completely fail for VAG COM to pick up a fault.

 

[DPJ]

Vag-com can only fault codes that are stored on the relevant ecu module.

The N75 isn't sophisticated, it's just a solenoid, so it will only throw a fault code when it completely fails.

I think the only fault codes it can throw are
17954 P1546 Boost Pressure Contr.Valve Short to B+
17955 P1547 Boost Pressure Contr.Valve Short to Ground
17956 P1548 Boost Pressure Contr.Valve Open
17957 P1549 Boost Pressure Contr.Valve Short to Ground

Defective operation will show up elsewhere, in logging etc.

 

[waynepixel]

Vag-com can only fault codes that are stored on the relevant ecu module.

The N75 isn't sophisticated, it's just a solenoid, so it will only throw a fault code when it completely fails.

I think the only fault codes it can throw are
17954 P1546 Boost Pressure Contr.Valve Short to B+
17955 P1547 Boost Pressure Contr.Valve Short to Ground
17956 P1548 Boost Pressure Contr.Valve Open
17957 P1549 Boost Pressure Contr.Valve Short to Ground

Defective operation will show up elsewhere, in logging etc.

Well I did logs last year and the only thing which looked out of place was the Block 115 for Actual Boost and requested Boost which suggested a boost leak somewhere, I did not get one error code, or even a suggestion from the logs I made that the N75 was at fault . As for the N75 being a solenoid I agree but the valve is still connected to the ECU so there must be some kind of error pickup from the ECU. When the N75 was faulty the performance of the car was very noticeable so I just think this is a little odd that VAG COM did not pick up any errors

 

[DPJ]

Faulty N75 operation is usually picked up by looking at Duty Cycle and engine loads.