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.
2017 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE
Electrical Specification
WARNING: This page is about a different variant/trim than selected.
| Description | Connector No. | Terminal No. | Signal (V) | Note | ||
|---|---|---|---|---|---|---|
| Ignition SW ON (Engine OFF) | Engine ON (Idling) | |||||
| Crankshaft position sensor | (+) signal | B137 | 17 | 0 | -7 - +7 | *1: Waveform |
| (-) signal | B137 | 25 | 0 | 0 | - | |
| Shield | B137 | 31 | 0 | 0 | - | |
| Front oxygen (A/F) sensor | (+) signal | B136 | 19 | 2.8 - 3.2 | 2.8 - 3.2 | - |
| (-) signal | B136 | 18 | 2.4 - 2.7 | 2.4 - 2.7 | - | |
| Rear oxygen sensor | Signal | B136 | 20 | 0 | 0 - 0.9 | - |
| Oxygen sensor | Shield | B136 | 9 | 0 | 0 | - |
| Front oxygen (A/F) sensor heater | Signal 1 | B136 | 6 | - | - | Waveform |
| Signal 2 | B136 | 5 | - | - | Waveform | |
| Rear oxygen sensor heater signal | B135 | 6 | Battery voltage | Battery voltage | Waveform | |
| Engine coolant temperature sensor | Signal | B137 | 22 | 1 - 1.4 | 1 - 1.4 | - |
| Air flow sensor | (+) signal | B136 | 22 | - | 0.3 - 4.5 | - |
| Shield | B136 | 10 | 0 | 0 | - | |
| Ground | B136 | 11 | 0 | 0 | - | |
| Intake air temperature sensor signal | B136 | 31 | 0.3 - 4.6 | 0.3 - 4.6 | - | |
| Wastegate control solenoid valve | B134 | 33 | 0 or battery voltage | 0 or battery voltage | Waveform | |
| Starter switch | B136 | 16 | 0 | 0 | Model without push button start Cranking: Battery voltage Model with push button start Cranking: Waveform | |
| Accessory cut request | B135 | 32 | Battery voltage | Battery voltage | Model with push button start Cranking: 0 | |
| Starter switch 2 | B136 | 27 | 0 | 0 | Model with push button start Cranking: Battery voltage | |
| Starter cut relay | B135 | 34 | 0 | 0 | Model with push button start Cranking: Battery voltage | |
| Ignition switch | B136 | 30 | Battery voltage | Battery voltage | - | |
| Neutral position switch | B136 | 35 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | - | |
| Delivery mode switch | B136 | 34 | Battery voltage | Battery voltage | When connected: 0 | |
| Knock sensor | Signal | B137 | 2 | 2.45 - 2.55 | 2.45 - 2.55 | - |
| Shield | B137 | 8 | 0 | 0 | - | |
| Back-up power supply | B136 | 2 | Battery voltage | Battery voltage | Ignition switch "OFF": Battery voltage | |
| Control module power supply | B136 | 1 | Battery voltage | Battery voltage | - | |
| B137 | 7 | Battery voltage | Battery voltage | - | ||
| Sensor power supply | B134 | 19 | 5 | 5 | - | |
| B135 | 22 | 5 | 5 | - | ||
| Ignition control | #1 | B134 | 21 | 0 | 0 or 5 | Waveform |
| #2 | B134 | 22 | 0 | 0 or 5 | Waveform | |
| #3 | B134 | 31 | 0 | 0 or 5 | Waveform | |
| #4 | B134 | 32 | 0 | 0 or 5 | Waveform | |
| Fuel injector | #1 | B134 | 10 | Battery voltage | 0 or battery voltage | Waveform |
| #2 | B134 | 11 | Battery voltage | 0 or battery voltage | Waveform | |
| #3 | B134 | 12 | Battery voltage | 0 or battery voltage | Waveform | |
| #4 | B134 | 13 | Battery voltage | 0 or battery voltage | Waveform | |
| Fuel pump control unit | Control | B136 | 33 | 0 or 5 | 0 or 5 | Waveform |
| Diagnostic signal | B135 | 10 | Battery voltage | Battery voltage | - | |
| A/C relay control | B135 | 35 | ON: 0.5 or less OFF: Battery voltage | ON: 0.5 or less OFF: Battery voltage | - | |
| A/C switch | B136 | 29 | ON: Battery voltage OFF: 0 | ON: Battery voltage OFF: 0 | Manual A/C model | |
| Blower fan switch | B135 | 19 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | Manual A/C model | |
| Main fan relay control | B135 | 12 | ON: 0.5 or less OFF: Battery voltage | ON: 0.5 or less OFF: Battery voltage | - | |
| Sub fan relay control | B135 | 11 | ON: 0.5 or less OFF: Battery voltage | ON: 0.5 or less OFF: Battery voltage | - | |
| Engine speed output | B135 | 15 | - | 0 or battery voltage | Model with push button start Waveform | |
| Purge control solenoid valve 1 | B137 | 6 | ON: 1 or less OFF: Battery voltage | ON: 1 or less OFF: Battery voltage | Waveform | |
| Purge control solenoid valve 2 | B137 | 15 | ON: 1 or less OFF: Battery voltage | ON: 1 or less OFF: Battery voltage | Waveform | |
| Manifold absolute pressure sensor | Signal | B137 | 20 | 1.7 - 2.4 | 1.1 - 1.6 | - |
| Power steering oil pressure switch | B137 | 28 | Battery voltage | ON: 0 OFF: Battery voltage | - | |
| SSM/GST communication line | B135 | 14 | - | - | - | |
| Intake camshaft position sensor RH | B137 | 24 | 0 or 5 | 0 or 5 | *1: Waveform | |
| Intake camshaft position sensor LH | B137 | 16 | 0 or 5 | 0 or 5 | *1: Waveform | |
| Exhaust camshaft position sensor RH | B137 | 23 | 0 or 5 | 0 or 5 | *1: Waveform | |
| Exhaust camshaft position sensor LH | B137 | 29 | 0 or 5 | 0 or 5 | *1: Waveform | |
| Camshaft position sensor ground | B137 | 30 | 0 | 0 | - | |
| Electronic Throttle | Main | B134 | 18 | Approx. 0.9 | Approx. 0.6 - 0.7 | Fully closed: Approx. 0.6 Fully open: Approx. 4.0 |
| Sub | B134 | 28 | Approx. 1.7 | Approx. 1.5 - 1.6 | Fully closed: Approx. 1.5 Fully open: Approx. 4.2 | |
| (+) Electronic throttle control motor | B134 | 2 | Duty waveform | Duty waveform | Drive frequency: 500 Hz | |
| (-) Electronic throttle control motor | B134 | 1 | Duty waveform | Duty waveform | Drive frequency: 500 Hz | |
| Electronic throttle control motor power supply | B135 | 7 | Battery voltage | Battery voltage | - | |
| Electronic throttle control motor relay | B135 | 17 | 0 | 0 | - | |
| Intake oil flow control solenoid valve RH | (+) signal | B134 | 34 | 0 | 0 or battery voltage | - |
| (-) signal | B134 | 27 | 0 | 0 | - | |
| Intake oil flow control solenoid valve LH | (+) signal | B134 | 17 | 0 | 0 or battery voltage | - |
| (-) signal | B134 | 16 | 0 | 0 | - | |
| Exhaust oil flow control solenoid valve RH | (+) signal | B134 | 7 | 0 | 0 or battery voltage | - |
| (-) signal | B134 | 15 | 0 | 0 | - | |
| Exhaust oil flow control solenoid valve LH | (+) signal | B134 | 5 | 0 | 0 or battery voltage | - |
| (-) signal | B134 | 14 | 0 | 0 | - | |
| Accelerator pedal position sensor | Main sensor signal | B135 | 23 | Fully closed: 0.4 - 1 Fully opened: 2.4 - 3.7 | Fully closed: 0.4 - 1 Fully opened: 2.4 - 3.7 | - |
| Main power supply | B135 | 21 | 5 | 5 | - | |
| Ground (main sensor) | B135 | 29 | 0 | 0 | - | |
| Sub sensor signal | B135 | 31 | Fully closed: 0.3 - 1.1 Fully opened: 2.3 - 3.8 | Fully closed: 0.3 - 1.1 Fully opened: 2.3 - 3.8 | - | |
| Starter relay | B135 | 26 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | ON: Cranking | |
| A/C middle pressure switch | B136 | 7 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | - | |
| Clutch switch | B135 | 9 | When clutch pedal is depressed: 0 When clutch pedal is released: Battery voltage | When clutch pedal is depressed: 0 When clutch pedal is released: Battery voltage | - | |
| Brake switch 1 (Brake switch) | B136 | 15 | When brake pedal is depressed: 0 When brake pedal is released: Battery voltage | When brake pedal is depressed: 0 When brake pedal is released: Battery voltage | - | |
| Brake switch 2 (Stop light switch) | B136 | 3 | When brake pedal is depressed: Battery voltage When brake pedal is released: 0 | When brake pedal is depressed: Battery voltage When brake pedal is released: 0 | - | |
| Cruise control command switch | B136 | 12 | When operating nothing: 3.5 - 4.5 When operating RES/ACC: 2.5 - 3.5 When operating SET/COAST: 0.5 - 1.5 When operating CANCEL: 0 - 0.5 | When operating nothing: 3.5 - 4.5 When operating RES/ACC: 2.5 - 3.5 When operating SET/COAST: 0.5 - 1.5 When operating CANCEL: 0 - 0.5 | - | |
| Cruise control main switch | B136 | 13 | ON: 0 OFF: 5 | ON: 0 OFF: 5 | - | |
| Immobilizer signal | B135 | 25 | - | - | - | |
| CAN communication (Hi) | B136 | 17 | - | - | - | |
| CAN communication (Lo) | B136 | 28 | - | - | - | |
| Blow-by leak diagnosis | B137 | 12 | 0 | 0 | At the time of open circuit (fault): 5 | |
| Tumble generator valve position sensor signal RH | B137 | 11 | Fully closed: 0.4 - 1.2 Fully opened: 2.8 - 4.6 | Fully closed: 0.4 - 1.2 Fully opened: 2.8 - 4.6 | - | |
| Tumble generator valve position sensor signal LH | B137 | 10 | Fully closed: 0.4 - 1.2 Fully opened: 2.8 - 4.6 | Fully closed: 0.4 - 1.2 Fully opened: 2.8 - 4.6 | - | |
| Tumble generator valve RH closed | B134 | 26 | Waveform | Waveform | - | |
| Tumble generator valve LH closed | B134 | 24 | Waveform | Waveform | - | |
| Tumble generator valve RH open | B134 | 25 | Waveform | Waveform | - | |
| Tumble generator valve LH open | B134 | 23 | Waveform | Waveform | - | |
| Secondary air pipe pressure sensor | Signal | B137 | 9 | 2.2 - 2.8 | 2.2 - 2.8 | When secondary air is inducted: 3.2 - 4.9 |
| Secondary air combination valve relay 1 | B135 | 8 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | - | |
| Secondary air combination valve relay 2 | B135 | 20 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | - | |
| Secondary air pump relay | B135 | 27 | ON: 0 OFF: Battery voltage | ON: 0 OFF: Battery voltage | - | |
| Self-shutoff control | B135 | 13 | Battery voltage | Battery voltage | - | |
| Leak check valve assembly | Switching valve | B135 | 4 | Battery voltage | Battery voltage | Operating: 0 |
| Pressure sensor | B136 | 21 | 1 - 4 | 1 - 4 | When ignition switch is turned to ON: atmospheric pressure | |
| Vacuum pump | B137 | 27 | Battery voltage | Battery voltage | Operating: 0 | |
| Ground | Sensor | B134 | 29 | 0 | 0 | - |
| B135 | 30 | 0 | 0 | - | ||
| Engine 1 | B134 | 6 | 0 | 0 | - | |
| Engine 2 | B134 | 4 | 0 | 0 | - | |
| Engine 3 | B134 | 3 | 0 | 0 | - | |
| Engine 4 | B137 | 1 | 0 | 0 | - | |
| Engine 5 | B137 | 3 | 0 | 0 | - | |
| Body | B136 | 4 | 0 | 0 | - | |
Measuring condition:
NOTE:
- Perform measurement after warming up the engine.
- For measurement of the waveform of the crankshaft position sensor, we recommend using the DST-i oscilloscope function or a general oscilloscope.
- Place the shift lever in neutral position.
- Turn the A/C to OFF.
- Turn all the accessory switches to OFF.
- Waveforms vary depending on a measurement environment and vehicle condition.
*1: Waveform
| Measured terminal | Crankshaft position sensor (+) signal (B137) No. 17 (+) - Engine ground 3 (B134) No. 3 (-): |
| Intake camshaft position sensor RH (B137) No. 24 (+) - Engine ground 3 (B134) No. 3 (-): | |
| Intake camshaft position sensor LH (B137) No. 16 (+) - Engine ground 3 (B134) No. 3 (-): | |
| Exhaust camshaft position sensor RH (B137) No. 23 (+) - Engine ground 3 (B134) No. 3 (-): | |
| Exhaust camshaft position sensor LH (B137) No. 29 (+) - Engine ground 3 (B134) No. 3 (-): | |
| Measuring condition | While engine idling |
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:
- • 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.
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