Title:2006/06/14PIC3959 DTC B0283 05 Setting Saab 9-3 Combi

Date: 06/14/2006
To: Service Department
From: Technical Assistance

[FONT=Arial]Date[/FONT][FONT=Arial] June 14, 2006[/FONT]

[FONT=Arial]Subject[/FONT][FONT=Arial]: DTC B028305 Setting Saab 9-3 Combi[/FONT]

[FONT=Arial]2006 Saab 9-3 Combi[/FONT]

[FONT=Arial]The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.[/FONT]

[FONT=Arial]A technician may state he has an unwanted alarm activation. A "SERVICE ANTI-THEFT ALARM" message is displayed in SID and a code of B028305 (Glass Breakage Detector Open/Short to B+) may have set. The tech may state the vehicle is not equipped with the Ultrasonic sensor and he has gone into the BCM and reprogrammed it "without" the Ultrasonic sensor but has no change in the concern.[/FONT]
[FONT=Arial] [/FONT]
[FONT=Arial]A new mechanical type of glass break sensor that consist of a defroster type grid in the 3 rear window glasses that are installed in the 9-3 Combi only. These are activated by the glass breaking and severing the circuit. This is not to be confused with the Ultrasonic sensor that was mounted in the overhead console. The correct answer to programming the BCM is still" Without" for MY2006, as the sensor was deleted for Mid-MY2005. This sensor is a simple ground circuit that measures continuity across the 3 windows. There are connectors at the base of each window that look similar to a 9-volt battery connector that are connected in series from ground G52 to 765RR to H8-10 to 765RC to H8-10 to 756RL to H102-1 to pin A31 BCM.[/FONT]
[FONT=Arial] [/FONT]
[FONT=Arial]NOTE: See WIS 2006/9440/Theft Protection/Technical Description/Glass Breakage Loop (765) for description of operation.[/FONT]

Main task

Used by the anti-theft alarm to detect whether one of the rear side windows or the rear window has been broken.

If an attempt is made to break in the entire pane will crack because it is hardened. The glass breakage loop will also crack and this is detected by BCM, which activates the anti-theft alarm.


Glass breakage loop


The glass breakage loops for the rear side windows (765RL/RR) and the rear window (765RC) are connected in series from BCM pin A31 to the rear left side window glass breakage loop (765RL) and then to the rear window glass breakage loop (765RC), which is connected to the rear right side window glass breakage loop (765RR). The glass breakage loop for the right side window (765RR) is connected to grounding point G34S via crimp J108.

The input for the glass breakage loop in BCM is an A/D converter with pull up resistor (1.2 kohm) to 10V. The PWM voltage pulses have a length of 3 ms and frequency 2 pulses per second. As long as the loops are intact, the voltage on the input is close to 0V but rises to almost 10V if they are broken.