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.
2023 Subaru WRX Base, Standard TransFACTORY OEM SERVICE PROCEDURE
Electrical Specification
NOTE:
- Terminal numbers in VDCCM & H/U connector (on the control module side) are shown in the figure.
- When the connector is removed from the VDCCM & H/U, the brake warning light (EBD warning light)/parking brake warning light, ABS warning light, VDC warning light & VDC indicator light and VDC OFF indicator light illuminate.
| Terminal No. | Contents | Measuring condition | Standard | ||||
|---|---|---|---|---|---|---|---|
| (B66) No. 1 ββ Chassis ground | VDC pump motor power supply | Always | Battery voltage | ||||
| (B66) No. 2 | RH rear brake caliper (+)(1) | - | - | ||||
| (B66) No. 3 | RH rear brake caliper (-)(1) | - | - | ||||
| (B66) No. 5 | Power unit 1 CAN H signal | - | - | ||||
| (B66) No. 7 | FL wheel speed sensor GND | - | - | ||||
| (B66) No. 8 ββ Chassis ground | Electronic parking brake indicator light(1) | Always | Battery voltage | ||||
| (B66) No. 11 | (G)_Chassis CAN H signal | - | - | ||||
| (B66) No. 12 | LH rear brake caliper (-)(1) | - | - | ||||
| (B66) No. 13 | LH rear brake caliper (+)(1) | - | - | ||||
| (B66) No. 14 | Ground | - | - | ||||
| (B66) No. 15 | Electronic parking brake switch(1) | - | - | ||||
| (B66) No. 16 | Electronic parking brake switch(1) | - | - | ||||
| (B66) No. 19 | Power unit 1 CAN L signal | - | - | ||||
| (B66) No. 20 ββ Chassis ground | Brake booster pressure sensor power supply(2) | Ignition switch: ON | 4.85 - 5.15 V | ||||
| (B66) No. 21 | FR wheel speed sensor signal | - | - | ||||
| (B66) No. 22 | RR wheel speed sensor signal | - | - | ||||
| (B66) No. 23 | RL wheel speed sensor GND | - | - | ||||
| (B66) No. 24 | FL wheel speed sensor signal | - | - | ||||
| (B66) No. 25 | (G)_Chassis CAN L signal | - | - | ||||
| (B66) No. 26 | FR wheel speed sensor GND | - | - | ||||
| (B66) No. 27 ββ Chassis ground | Brake fluid level switch | Ignition switch: ON | 6 V or more | ||||
| (B66) No. 28 | Brake booster pressure sensor GND(2) | - | - | ||||
| (B66) No. 30 ββ Chassis ground | VDCCM power supply | Always | Battery voltage | ||||
| (B66) No. 31 | Electronic parking brake switch(1) | - | - | ||||
| (B66) No. 32 | Electronic parking brake switch(1) | - | - | ||||
| (B66) No. 33 ββ Chassis ground | Stop light switch output | Ignition switch: ON | Ignition power supply voltage | ||||
| (B66) No. 34 | VSO PIN output | - | - | ||||
| (B66) No. 35 | VSO PIN output | - | - | ||||
| (B66) No. 36 ββ Chassis ground | Ignition power supply | Ignition switch: ON | Ignition power supply voltage | ||||
| (B66) No. 37 | RR wheel speed sensor GND | - | - | ||||
| (B66) No. 38 ββ Chassis ground | Stop light switch | Brake pedal operation | Brake ON: Battery voltage Brake OFF: Ground |
||||
| (B66) No. 39 | RL wheel speed sensor signal | - | - | ||||
| (B66) No. 41 ββ Chassis ground | VDC OFF switch | VDC OFF switch operation | Switch ON: 1 Ξ© or less Switch OFF: 1 MΞ© or more |
||||
| (B66) No. 45 | Brake booster pressure sensor signal(2) | - | - | ||||
| (B66) No. 46 | Ground | - | - | ||||
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Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.