VW Passat 1,9 Tdi 1Z 5 Fehler u. a. G70 G81 G62 | Beiträge 16+

Hi,
I'll try it with the successor model. There's a version with the AHU in the electrical diagrams, dating back to 1996. The AHU and 1Z are essentially the same.
hg
Herbert

Good morning!
I am describing the mass connections for measurement:
From the engine control unit J 248 connector T 68 pin 33 1mm brown/white, to point 220 (in the engine cable harness), further to G81 connector T8a pin 4 1mm brown/white, from point 220 to G 70 pin 2 0.5mm brown/white, from point 220 to G 28 connector T3 pin 1 0.35mm, and to G 72 pin 2 0.5mm brown white, and to G 62 pin 3 0.5mm brown/white.
This imaginary point 220 should be in the engine harness, and there must be a connection (solder/terminal) for the different cable cross-sections.
For Passat MKB AHU from 10/1996.
I hope this helps.
Best regards,
TDI-Erwin

Hello,

The wiring diagram for the 1Z is still available and can be downloaded on the Audi portal.

Fuel temperature sensor:

The value of -5.6°C is a replacement value. (In case of a wiring fault)

8-pin connector

Pin 4 to Pin 33 of the engine ground

Pin 7 to Pin 63 of the engine

Pin 63, when ignition is on, check against ground 1.5 - 3.5 volts

Coolant temperature sensor

4-pin connector

Pin 1 to Pin 33 engine

Pin 3 to Pin 14 engine

Pin 14 at ignition on against ground at 80°C, approximately 1.5 - 3.5 volts. As the temperature increases (80°C), the voltage decreases to approximately 1.5 volts.

The pedal sensor and LMM are also connected to pin 33.

Best regards,
Michael

Hello everyone.

So, to Erwin: At the A-pillar, below the trim, where the motor cover release is located, I have a tangled bundle of ground cables. That's where it ends. I'll pick up the car again and continue searching.

To Nixkönner: Thanks for the information, I'll get back to it later.

Hi,

The uncertainty regarding the wiring diagrams can be overcome. In the RLF's for the Passat, you will find a section titled "Diesel Direct Injection and Preheating System", which specifies how to test the temperature sensors and wiring to the MSG, along with contact designations for a test box between the MSG and the connector. These contact designations must match the MSG.

This allows you to test each wire, including for continuity from positive or ground.

You can also find the R/T curves for the temperature sensors in the RLF.

And please remember that pin 33 is a common reference point for some sensors on the MSG, but it does not necessarily have to be ground.
hg
Herbert

I also found Herbert. However, the description only covers the testing process using the vag tester. Best regards.

You can simply measure with a multimeter between the contacts on the MSG connector and the corresponding sensor.
You don't need a VAG measuring instrument.
hg
Herbert