Heated Windshield Z2, checking activation

WARNING: This page is about a different car, the 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and equipment

Test Box V.A.G 1598A as well as corresponding Adapter V.A.G 1598/11 and Adapter - 16 Terminals V.A.G 1598/12
Diagnostic Operation System VAS 5051A (with Multimeter Leads VAS 5051/7)
Connector Test Set V.A.G 1594C

Switch off ignition.
Remove operating and display module, Climatronic Control Module J255.

Fig 1: VAG 1598 Test Box With VAG 1598/11 And VAG 1598/12 Adapter Cables

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Connect Test Box V.A.G 1598A with appropriate Adapter V.A.G 1598/11 between connector - C - and operating and display module, Climatronic Control Module J255 → Wiring and component check using Test Box V.A.G 1598A .
Connect Adapter - 16 Terminals V.A.G 1598/12 between connector - D - and operating and display module, Climatronic Control Module J255 (use second Test Box V.A.G 1598A or connect measuring instrument with suitable test lead from Connector Test Set V.A.G 1594C directly to Adapter - 16 Terminals V.A.G 1598/12) → Wiring and component check using Test Box V.A.G 1598A .

NOTE:

The terminal assignment of the connector - C - for the Adapter V.A.G 1598/11 and the connector - D - for the Adapter - 16 Terminals V.A.G 1598/12 is identical to the assignment of the sockets at the Test Box V.A.G 1598A.

Start engine.

NOTE:

All connectors must be plugged in at the operating and display module, Climatronic Control Module J255.

Measure voltage between contact "8" in connector - C - (from Heated Windshield Control Module J505) and contact "16" in connector - D - (Ground (GND) connection).

Specified value: approx. Battery voltage
If a voltage of less than 5 V is measured, the Heated Windshield Control Module J505 is currently not ready to activate the Heated Windshield or there is a short to Ground (GND) in the connection to the Heated Windshield Control Module J505 → Heated Windshield Z2, function .
If a voltage of between 5 V and 8 V is measured, the operating and display module, Climatronic Control Module J255 is activating the Heated Windshield Control Module J505 and this has activated the Heated Windshield.