Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
System overview: Signals
The chart below summarizes input and output signals to and from the power seat module (4/52). The signal types are divided into directly connected signals, serial communication and Control area network (CAN) communication. The illustration below displays the same information with the Volvo part numbers.
| Input signals | Output signals |
| Directly connected: | Directly connected: (power supply unless otherwise stated) |
| Control panel (3/26) with: | Seat motors (6/16-19) (four) |
|
Voltage supply signal EXT.X |
| Hall sensors (four integrated in the seat motor) | |
| Control circuit connected to the control panel | |
| Via Control Area Network (CAN): | Via Control Area Network (CAN): |
| Central electronic module (4/56) | Passenger door module (3/126) |
| Upper electronic module (4/70) | Driver's door module (3/127) |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.