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.
Vehicle Electrical System Control Module, Data Bus On Board Diagnostic Interface, Engine/Motor Control Module
J519 - Vehicle Electrical System Control Module
J533 - Data Bus on Board Diagnostic Interface
J623 - Engine/Motor Control Module
T17h - 17-Pin Connector, Brown
T17j - 17-Pin Connector, Brown
T20a - 20-Pin Connector, Red
T73a - 73-Pin Connector, Black
T73c - 73-Pin Connector, Black
T91 - 91-Pin Connector, Black
TIUL - Coupling Point in Interior, Bottom Left
A236 - CAN Bus Drive High Connection 1 (in Instrument Panel Wiring Harness)
A237 - CAN Bus Drive Low Connection 1 (in Instrument Panel Wiring Harness)
E123 - CAN Bus Drive High Connection 1 (in Engine Wiring Harness)
E124 - CAN Bus Drive Low Connection 1 (in Engine Wiring Harness)
E125 - CAN Bus Drive High Connection 2 (in Engine Wiring Harness)
E126 - CAN Bus Drive Low Connection 2 (in Engine Wiring Harness)
* - For Vehicles with Automatic Transmission (DSG)
*2 - For LHD Vehicles
*3 - For Vehicles Without Engine Remote Start
*4 - For RHD Vehicles
*5 - Refer to Applicable Wiring Diagram for Ground Concept in Vehicle Interior
*6 - Refer to Applicable Wiring Diagram for Fuses in Vehicle Interior
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.