Help please N75 problems TDi 130 AWX

[Metallurgix]

Passat b5.5 130ps Tdi AWX engine. N75 defective?

I have a late passat b5.5, first registered September 2005. It does not perform as it should and in particular lacks torque at low and medium RPM. Investigating the MAP valve and pipework revealed the following.

1. With the ignition turned off it was easy to suck air through the vacume line from the turbo actuator. The resistance was what you might expect for the length and bore of the pipes. Turning the ignition on made no difference.
2. With the engine idling and the vacume pipe connected the actuator moved 10 – 11 mm. With the pipe disconnected there was some vacume evident in the pipe. Also there was a partial vacume present in the vent pipe from the N75 valve which connects to the air filter unit.



3. Checking the electrics. The 2 pin connecter was tested as follows.

1. With the ignition turned off. The resistance between earth and the red/white (to terminal 1) was around 433 W that between the brown and yellow lead (to the controller) and earth was > 20kW.
2. With the ignition turned on the resistance for both was >20 kW and the voltage between these terminals and earth was as follows: red and white 11.9 V, Brown and yellow 3.3 V. The voltage between the two terminals was 8.5 V (which is consistent). There was no current measured on a 200 mA scale.

Does anyone know how the N75 should behave on this model and if it’s wrong what I can do about it. I have a legal full version of VCDS although I only know how to use a fraction of it. I’m interested in learning.

[martin1810]

Use your vcds to run some measuring block scans. There is info on my site to help with this.