[elgyqc]

AI provided the following information on the airbag module pinouts. I take anything that comes from AI with a dose of scepticism:
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While factory schematics divide the airbag system into sub-circuits across multiple pages, the comprehensive pinout configuration for the Temic 996.618.219.01 (MRSZ2-P) module used in the 2000 Porsche 986 Boxster breaks down as follows.
The unit utilizes a single 50-pin plug housing divided into two physical rows (Pins 1–25 and Pins 26–50).
Power, Ground, and Data Lines
• Pin 5: Chassis Ground (Terminal 31)
• Pin 6: Switched Ignition Power (+12V from Fuse E1, Terminal 15)
• Pin 9: K-Line Diagnostic Data (Routed to Pin 3 of the car's OBD2 connector)
• Pin 7: Instrument Cluster Airbag Warning Light output (Triggers the warning bulb at Cluster Pin B25)
Sensor and Airbag Deployment Loops
The 2000 model year Boxster features driver/passenger front airbags, door-mounted side airbags, and dual seatbelt pyrotechnic tensioners.
• Pins 1 & 2: Driver Side Airbag (Steering Wheel Squib)
• Pins 3 & 4: Passenger Side Airbag (Dashboard Squib)
• Pins 27 & 28: Driver Side Thorax Airbag (Door-mounted)
• Pins 29 & 30: Passenger Side Thorax Airbag (Door-mounted)
• Pins 11 & 12: Driver Seatbelt Tensioner (Pyrotechnic buckle)
• Pins 13 & 14: Passenger Seatbelt Tensioner (Pyrotechnic buckle)
• Pins 33 & 34: Left Side Crash Sensor connection (Satellite sensor)
• Pins 35 & 36: Right Side Crash Sensor connection (Satellite sensor) [1, 2]
Seatbelt Buckle Switches (TSB #6924 Loop)
These pins monitor the microswitches inside the seatbelt receivers to determine if a passenger is buckled. Resistance faults here are the primary cause of the common intermittent Porsche airbag light:
• Pin 19: Driver Seatbelt Buckle Switch Signal
• Pin 20: Driver Seatbelt Buckle Switch Ground
• Pin 21: Passenger Seatbelt Buckle Switch Signal
• Pin 22: Passenger Seatbelt Buckle Switch Ground [1]
Unassigned Pins
• Pins 8, 10, 15–18, 23–26, 31–32, and 37–50: Empty / Not Used on the 986 base configuration (reserved for optional child-seat deactivation bars or later model updates). [1]
Note: All unlisted pins on this specific unit are blank slots in the wire loom harness plug.
If you are diagnosing a fault, tell me if you have a specific DTC code number (e.g., Code 44 or Code 46 for belt buckles), or let me know if you are tracing a broken wire harness beneath the seats.


Step-by-Step Troubleshooting Flow
1. Verify Module Resistance (On the Bench or Unplugged)
◦ Disconnect the vehicle's battery and wait at least 20 minutes before working on the airbag system.
◦ If testing on the bench, a diagnostic tool will read an open circuit fault for the driver's airbag because nothing is connected to Pin 1 and Pin 2. If you place a 2.0 to 2.5-ohm resistor across Pin 1 and Pin 2 on your bench harness, Code 21 should turn from "Active" to "Intermittent," allowing you to clear it. This confirms your Temic module's internal circuitry is working perfectly. [1]
2. Inspect Steering Wheel Connections (In the Car)
◦ Remove the two Torx screws from the back of the steering wheel to lift the driver’s airbag module free.
◦ Check the small orange/maroon plug directly on the back of the airbag canister. Ensure it is fully clicked in and the locking tab is seated.
3. Test/Replace the Clockspring
◦ If the wheel plugs are clean, the break is inside the steering column clockspring.
◦ Note: Do not attempt to test the clockspring continuity with a standard multimeter while it is still plugged into the live airbag module, as the small electrical current from the meter can theoretically deploy the squib.
◦ Replacing the clockspring requires removing the steering wheel center nut. When installing a replacement unit, pay strict attention to the centering arrows on the plastic face of the replacement clockspring so it doesn't snap the first time you lock the steering wheel to one side.