Heated Rear Window -Z1-, Testing
Heated Rear Window Z1 , Testing
NOTE:
- If a condition exists which prevents activation of the Heated Rear Window (short circuit in connection to rear window or to Rear Window Defogger Relay J9, open circuit in power supply to operating and display module, Climatronic Control Module J255 or open convertible top with Cabrio), the indicator lamp in the button lights on pressing the button in the operating and display module, Climatronic Control Module J255 and goes out again on releasing the button, however the heating is not activated.
- If the voltage measured by the operating and display module, Climatronic Control Module J255 at terminal "30" drops below 12.5 V, the power of the Heated Rear Window is reduced, thus relieving the load on the Generator (GEN) (the electronic system of the operating and display module, Climatronic Control Module J255 reduces the activation duty cycle from 100% to 90 to 10%).
- On vehicles up to VIN 399999 in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 without prior specification of any particular VIN), the Heated Rear Window Z1 is activated directly by the operating and display module, Climatronic Control Module J255 (the relay for switching the current is installed in the operating and display module, Climatronic Control Module J255).
- On vehicles as of VIN 400000 in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 without prior specification of any particular VIN), the Heated Rear Window Z1 will no longer be activated directly by the operating and display module, Climatronic Control Module J255 (operating and display modules, Climatronic Control Module J255 with part No. index "AJ" onwards are no longer installed with a relay). On these vehicles, the Heated Rear Window Z1 is activated via the Rear Window Defogger Relay J9.
- At ambient temperatures below 0 degree C, the Heated Rear Window remains switched on until the ignition is switched off (manual deactivation is possible at any time). If the temperature during a driving cycle rises above 0 degree C, the Heated Rear Window Z1 is deactivated on completion of the operating period stored in the operating and display module, Climatronic Control Module J255 (approx. 12 minutes).
- At ambient temperatures greater than 0 degree C, activation of the Heated Rear Window Z1 is terminated automatically on completion of the operating period (approx. 12 minutes) stored in the operating and display module, Climatronic Control Module J255 via the operating and display module, Climatronic Control Module J255.
Special tools and equipment
- Diagnostic Operation System VAS 5051 A (with Inductive Pickup (50 Amp) VAS 5051/9 )
- Connector Test Set V.A.G 1594C
NOTE: All fuses OK
- Switch off ignition.
- Remove operating and display module, Climatronic Control Module J255.
- Disconnect connectors - D - and - F - from operating and display module, Climatronic Control Module J255.
- Connect test box Adapter -16 Terminals V.A.G 1598/12 to disconnected connector - D
- Connect Test Box V.A. G 1598A to Adapter -16 Term inals V.A.G 1598/12
Test for vehicles up to VIN "399999" in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 without prior specification of any particular VIN)
- Measure voltage between contact "5" at connector - F - and socket "13" (Ground (GND) connection) of test box.
- Specified value: approx. Battery voltage
- Measure resistance between contact 6 at connector - F - and socket "13" (Ground (GND) connection) of test box.
- Specified value: Resistance approx. 0.5 to 1.0 (ohms)
NOTE:
- As resistances of less than 10 ohms cannot be measured with sufficient accuracy using workshop equipment, it is not possible to establish a short circuit in the wiring or in the Heated Rear Window Z1.
- If the resistance value is too high, check wiring to Heated Rear Window Z1 for open circuit and eliminate open circuit.
- Plug connectors - D - and - F - to operating and display module, Climatronic Control Module J255 (all connectors are now plugged in at operating and display module, Climatronic Control Module J255 ).
- Guide wire to connector - F - contact "6" through Inductive Pickup (50 Amp) VAS 5051/9.
- On Diagnostic Operation System VAS 5051 A , set "Multi-meter measurement: inductive pickup (50 amp)" mode.
NOTE: All connectors must be plugged in at the operating and display module, Climatronic Control Module J255.
- Start engine.
- Switch on Heated Rear Window at the operating and display module, Climatronic Control Module J255 (indicator lamp in button lights).
- Specified value: Display switches from approx. 0 A to less than 25 A
- Wait approx. 12 minutes.
- Specified value: Display switches from less than 25 A to approx. 0 A (indicator lamp in button goes out)
NOTE:
- Interference on the current probe measuring leads 1 2 may cause a slight current to be displayed with the Heated Rear Window switched off.
- At ambient temperatures below 0 degree C, the Heated Rear Window Z1 remains switched on until the ignition is switched off (manual deactivation is possible at any time). If the temperature during a driving cycle rises above 0 degrees C, the Heated Rear Window is deactivated on completion of the operating period stored in the operating and display module, Climatronic Control Module J255 (approx. 12 minutes).
- At ambient temperatures greater than 0 degrees C, the Heated Rear Window is switched off automatically by the operating and display module, Climatronic Control Module J255 on completion of the operating period stored in the operating and display module, Climatronic Control Module J255 (approx. 12 minutes).
Test for vehicles as of VIN "400000" in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 without prior specification of any particular VIN)
- Measure voltage between socket "12" (terminal "30") and socket "13" (Ground (GND) connection) of test box.
- Specified value: approx. Battery voltage
- Measure resistance between contact "6" at connector - F - and socket "13" (Ground (GND) connection) of test box.
- Specified value: Resistance approx. 10 ohm to 100 (ohms)
NOTE:
- As resistances of less than 10 cannot be measured with sufficient accuracy using workshop equipment, it is not possible to establish a short circuit in the wiring or in the Heated Rear Window Z1.
- If the resistance value is too high, check wiring to Heated Rear Window Z1 for open circuit and eliminate open circuit.
- Plug connectors - D - and - F - to operating and display module, Climatronic Control Module J255 (all connectors are now plugged in at operating and display module, Climatronic Control Module J255 ).
- On Diagnostic Operation System VAS 5051 A , set "Multi-meter measurement, voltage measurement (20 V DC)" mode.
NOTE:
- All connectors must be plugged in at the operating and display module, Climatronic Control Module J255.
- Measure voltage between contact "6" at connector - F - and socket "13" (Ground (GND) connection) of test box.
- Specified value: Voltage less than 2 V
- Start engine.
- Switch on Heated Rear Window at the operating and display module, Climatronic Control Module J255 (indicator lamp in button lights).
- Specified value: Voltage switches from approx. 0 V to approx. Battery voltage (and Rear Window Defogger Relay J9 switches on Heated Rear Window Z1 )
NOTE: Activation for Heated Rear Window can be checked for example by placing hand on heater coil area of rear window (heater wires must become warm).
- Wait approx. 12 minutes.
- Specified value: Display switches from approx. Battery voltage to less than approx. 2 V (indicator lamp in button goes out)
NOTE:
- At ambient temperatures below 0 degree C, the Heated Rear Window Z1 remains switched on until the ignition is switched off (manual deactivation is possible at any time). If the temperature during a driving cycle rises above 0 degree C, the Heated Rear Window is deactivated on completion of the operating period stored in the operating and display module, Climatronic Control Module J255 (approx. 12 minutes).
- At ambient temperatures greater than 0 degree C, the Heated Rear Window is switched off automatically by the operating and display module, Climatronic Control Module J255 on completion of the operating period stored in the operating and display module, Climatronic Control Module J255 (approx. 12 minutes).