Heated Windshield, Checking Activation

Heated Windshield, Checking Activation

• The windshield defogger control module (J505) is activated by the Climatronic control module (J255) via the data bus. For this purpose, the request is first sent via the data bus to the data bus on board diagnostic interface (J533) and is then relayed to the comfort system central control module (J393). The comfort system central control module then relays the request to the windshield defogger control module which activates the heating of the windshield defogger (Z2). Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function and. The activation of the windshield defogger control module is displayed in the read measured values function of the Guided Fault Finding of the Climatronic control module using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function

• The read measured values function of the Guided Fault Finding of the comfort system central control module and the Climatronic control module, displays that a request is present and why this is not being implemented if applicable using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• Check the activation of the windshield defogger using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• Refer to => [ Windshield Defogger ] Windshield Defogger.

• If the resistance value calculated by the comfort system central control module (displayed as measured values) is greater than 2.4 ohms or less than 1.5 ohms, check the wire connection from the windshield defogger control module to the windshield defogger for short circuit or contact resistance using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.

• If the resistance value measured by the comfort system central control module is greater than 3.4 ohms or less than 1.4 ohms, the comfort system central control module does not activate the windshield defogger control module or does not activate the heating of the windshield defogger. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.