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.
Heat And Fresh Air Control Multi-Pin Connector Assignments
Special tools and workshop equipment required
- Test Box V.A.G 1598/42
- Test Adapter V.A.G 1598/47
- Template 1598/47-2
The 16-pin harness connector is not assigned.
5-Pin Harness Connector, (T5)
1 - 3rd blower speed
2 - 2nd blower speed
3 - 1st blower speed
4 - 4th blower speed
5 - Terminal X and depending on the vehicle equipment level Auxiliary Heater Operation Relay -J485-
20-pin Harness Connector, (T20c)
3 - Fresh/Recirculating Air Door Motor -V154-
6 - Fresh/Recirculating Air Door Motor -V154-
7 - Auxiliary Air Heater Control Module -J604-
8 - Rear window
11 - Heated Driver Seat Control Module -J131-
15 - Heated Front Passenger Seat Control Module -J132-
16 - Terminal 75 seat heater (optional)
18 - Terminal 30
19 - Terminal 15
20 - Terminal 31
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.