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Home >> Subaru >> 2016 >> WRX Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (Diagnostics) (2.0L) - Introduction >> Engine Control Module (ECM) I/O Signal >> Electrical Specification
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Electrical Specification

Fig 1: Identifying Engine Control Module (ECM) I/O Signal Connector Terminals
G10292539Courtesy of SUBARU OF AMERICA, INC.
Description Connector No. Terminal No. Signal (V) Remarks
Ignition SW ON (Engine OFF) Engine ON (Idling)
Crankshaft position sensor Signal E158 19 0 or 5 0 or 5 Waveforms 1 and 10
Ground E158 31 0 0 -
Intake camshaft position sensor (RH) E158 20 0 or 5 0 or 5 Waveform 1
Intake camshaft position sensor (LH) E158 21 0 or 5 0 or 5 Waveform 1
Exhaust camshaft position sensor (RH) E158 32 0 or 5 0 or 5 Waveform 1
Exhaust camshaft position sensor (LH) E158 33 0 or 5 0 or 5 Waveform 1
Camshaft position sensor ground E158 34 0 0 -
Front oxygen (A/F) sensor IP+ signal E158 15 2 - 3 2 - 4 Waveform 2
VS+ signal E158 27 2 - 3 3 - 5 Waveform 2
COM signal E158 39 2 - 3 3 - 4 -
Heater signal E159 9 Battery voltage 0 or battery voltage Waveform 4
Rear oxygen sensor + signal E158 16 2 - 3 2 - 3 Waveform 3
- signal E158 42 2 - 3 2 - 3 -
Heater signal E159 3 Battery voltage 0 or battery voltage Waveform 4
Air flow sensor Signal B134 16 0 1 -
Ground B134 28 0 0 -
Intake air temperature sensor (integrated with air flow sensor) E158 5 2 - 3 2 - 3 -
Engine coolant temperature sensor E158 38 1 - 3 1 - 3 -
Engine oil temperature sensor E158 2 1 - 3 1 - 3 -
Manifold absolute pressure sensor E158 4 2 1 -
Intake air temperature sensor (integrated with manifold absolute pressure sensor) E158 25 2 - 3 2 - 3 -
Fuel pressure sensor E158 6 1 1 -
Knock sensor 1 E158 14 2.5 2.5 -
Knock sensor 2 E158 26 2.5 2.5 -
Accelerator pedal position sensor Main power supply B134 30 5 5 -
Main signal B134 17 Fully closed: 0.4 - 1
Fully opened: 2.4 - 3.7		 Fully closed: 0.4 - 1
Fully opened: 2.4 - 3.7		 Waveforms 2, 3, 5 and 6
Main ground B134 31 0 0 -
Sub signal B134 29 Fully closed: 0.4 - 1
Fully opened: 2.4 - 3.7		 Fully closed: 0.4 - 1
Fully opened: 2.4 - 3.7		 -
Tumble generator valve actuator (RH) Position signal E158 40 1 1 Fully closed: 1
Fully opened: 3
Waveform 5
Motor open E159 14 0 0 When in operation: Waveform
Waveform 5
Motor closed E159 30 0 0 When in operation: Waveform
Waveform 5
Tumble generator valve actuator (LH) Position signal E158 41 3 3 Fully closed: 3
Fully opened: 1
Waveform 6
Motor open E159 6 0 0 When in operation: Waveform
Waveform 6
Motor closed E159 22 0 0 When in operation: Waveform
Waveform 6
Intake oil control solenoid (RH) E159 7 Battery voltage 0 or battery voltage Drive frequency: 300 Hz Waveform 7
Intake oil control solenoid (LH) E159 15 Battery voltage 0 or battery voltage Drive frequency: 300 Hz Waveform 7
Exhaust oil control solenoid (RH) E159 23 Battery voltage 0 or battery voltage Drive frequency: 300 Hz Waveform 7
Exhaust oil control solenoid (LH) E159 31 Battery voltage 0 or battery voltage Drive frequency: 300 Hz Waveform 7
Wastegate control solenoid valve E159 11 Battery voltage Battery voltage When in operation: 0 or battery voltage
Canister purge control solenoid valve 1 E159 4 Battery voltage Battery voltage When in operation: 0 or battery voltage
Waveform 9
Canister purge control solenoid valve 2 E159 12 Battery voltage Battery voltage When in operation: 0 or battery voltage
Waveform 9
Ignition control #1 E159 8 0 0 or 5 Waveform 10
#2 E159 16 0 0 or 5 Waveform 10
#3 E159 24 0 0 or 5 Waveform 10
#4 E159 32 0 0 or 5 Waveform 10
EGR control valve A+ E159 5 0 or battery voltage 0 or battery voltage -
A- E159 21 0 or battery voltage 0 or battery voltage -
B+ E159 13 0 or battery voltage 0 or battery voltage -
B- E159 29 0 or battery voltage 0 or battery voltage -
Fuel pump control unit Control signal B134 40 ON: 0 or battery voltage
OFF: 0		 0 or battery voltage Waveform 8
Diagnostic signal B134 44 ON: Battery voltage
OFF: 0		 Battery voltage -
High-pressure fuel pump (Hi) E158 10 2.5 - Measurement prohibited
High-pressure fuel pump (Lo) E158 22 2.5 - Measurement prohibited
Fuel injector Power supply 1 B134 36 Battery voltage Battery voltage -
Power supply 2 B134 48 Battery voltage Battery voltage -
#1 (+) E158 11 0 - Measurement is prohibited while the engine is running.
#1 (-) E158 12 0 -
#2 (+) E158 23 0 -
#2 (-) E158 24 0 -
#3 (+) E158 35 0 -
#3 (-) E158 36 0 -
#4 (+) E158 47 0 -
#4 (-) E158 48 0 -
Electronic throttle control Sensor power supply E158 18 5 5 -
Main signal E158 17 Fully closed: Approx. 0.7
Fully open: Approx. 3.9		 Fully closed: Approx. 0.7
Fully open: Approx. 3.9		 -
Sub signal E158 29 Fully closed: Approx. 4.4
Fully open: Approx. 1.1		 Fully closed: Approx. 4.4
Fully open: Approx. 1.1		 -
Ground E158 30 0 0 -
Motor power supply B134 11 Battery voltage Battery voltage -
Electronic throttle control motor (+) E159 2 0 Duty waveform Drive frequency: 10 kHz
Electronic throttle control motor (-) E159 1 0 Duty waveform Drive frequency: 10 kHz
Electronic throttle relay control B134 39 0 Duty waveform -
Starter relay control B134 14 Model with push button start: 3
Models without push button start: 0		 3 Cranking: Waveforms 11 and 12
Self-shutoff relay control B134 38 1 1 -
Starter cut relay control B134 13 Model with push button start: 0
Models without push button start: 3		 Model with push button start: 0
Models without push button start: 3		 Cranking: Waveform 11
Main fan relay control B134 37 Battery voltage Battery voltage When in operation: 0 or battery voltage
Sub fan relay control B134 25 Battery voltage Battery voltage When in operation: 0 or battery voltage
A/C relay control B134 1 Battery voltage Battery voltage When in operation: 0 or battery voltage
Starter switch B134 45 0 0 Model with push button start
Cranking: Waveform 11
Starter switch 2 B134 8 0 0 Cranking: Battery voltage
Ignition switch B134 32 Battery voltage Battery voltage -
Pressure switch B134 7 Battery voltage Battery voltage -
Neutral position switch B134 33 ON: 0
OFF: Battery voltage		 ON: 0
OFF: Battery voltage		 Switch is ON when select lever is in "P" range or "N" range.
Cruise control Main switch B134 20 ON: 0
OFF: 5		 ON: 0
OFF: 5		 -
Command switch B134 6 When operating nothing: 3.5 - 4.5
When operating RES/+: 2.5 - 3.5
When operating SET/-: 0.5 - 1.5
When operating CANCEL: 0 - 0.5		 When operating nothing: 3.5 - 4.5
When operating RES/+: 2.5 - 3.5
When operating SET/-: 0.5 - 1.5
When operating CANCEL: 0 - 0.5		 -
Clutch switch B134 34 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		 MT model
Brake switch 1 (Brake switch) B134 43 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) E158 8 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		 -
Oil level switch E158 44 0 0 Oil level LOW: Battery voltage
Accessory cut request B134 2 Model with push button start: Battery voltage
Models without push button start: 0		 Model with push button start: Battery voltage
Models without push button start: 0		 Cranking: 0
Waveform 11
Engine speed output B134 4 Battery voltage 0 or battery voltage Waveform 12
Generator control B134 26 0 or 6.4 0 or 6.4 -
CAN communication (Hi) B134 10 - - -
(Lo) B134 9 - - -
LIN communication E158 3 - - -
Immobilizer communication E158 43 - - -
Delivery mode switch E158 45 Battery voltage Battery voltage When the fuse is installed: 0
Control module power supply B134 12 Battery voltage Battery voltage -
B134 24 Battery voltage Battery voltage -
Back-up power supply B134 23 Battery voltage Battery voltage -
Sensor power supply B134 18 5 5 -
E159 19 5 5 -
ELCM Switching valve B134 27 Battery voltage Battery voltage Operating: 0
Pressure sensor B134 15 1 - 4 1 - 4 When ignition switch is turned to ON: atmospheric pressure
Vacuum pump B134 3 Battery voltage Battery voltage Operating: 0
Brake booster pressure sensor E158 13 1 - 2 1 - 2 When brake pedal is released.
Brake vacuum pump E158 1 0 0 -
Brake vacuum pump relay E158 37 Battery voltage Battery voltage -
Sensor ground B134 19 0 0 -
E159 27 0 0 -
Ground Engine 1 B134 35 0 0 -
Engine 2 B134 47 0 0 -
Engine 3 E159 10 0 0 -
Engine 4 E159 18 0 0 -
Engine 5 E159 26 0 0 -
Engine 6 E159 17 0 0 -
Engine 7 E159 25 0 0 -

Measuring condition: 

  1. Waveform 1
    Fig 2: Crankshaft Position Sensor, Camshaft Position Sensor RH And LH Waveform
    G10267494Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Crankshaft position sensor (E158) No. 19 - Engine ground 3 (E159) No. 10:
    Intake camshaft position sensor RH (E158) No. 20 - Engine ground 3 (E159) No. 10:
    Intake camshaft position sensor LH (E158) No. 21 - Engine ground 3 (E159) No. 10:
    Exhaust camshaft position sensor RH (E158) No. 32 - Engine ground 3 (E159) No. 10:
    Exhaust camshaft position sensor LH (E158) No. 33 - Engine ground 3 (E159) No. 10:
    Measuring condition While engine idling
  2. Waveform 2
    Fig 3: Front Oxygen (A/F) Sensor, Engine Speed And Electronic Throttle Control Opening Valve Waveform
    G10292541Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Front oxygen (A/F) sensor IP+ signal (E158) No. 15 (+) - Engine ground 3 (E159) No. 10:
    Front oxygen (A/F) sensor VS+ signal (E158) No. 27 (+) - Engine ground 3 (E159) No. 10:
    Accelerator pedal position sensor main signal (B134) No. 17 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition (a) accelerator pedal fully closed (b) accelerator pedal half open (c) accelerator pedal fully opened
  3. Waveform 3
    Fig 4: Rear Oxygen Sensor, Engine Speed And Electronic Throttle Opening Valve Waveform
    G10292542Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Rear oxygen sensor (E158) No. 16 (+) - (E158) No. 42 (-):
    Accelerator pedal position sensor main signal (B134) No. 17 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition (a) accelerator pedal fully closed (b) accelerator pedal fully opened
  4. Waveform 4
    Fig 5: Front And Rear Oxygen (A/F) Sensor Heater Signal Waveform
    G10292543Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Front oxygen (A/F) sensor heater (E159) No. 9 (+) - Engine ground 3 (E159) No. 10:
    Rear oxygen sensor heater (E159) No. 3 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition While engine idling
  5. Waveform 5
    Fig 6: Tumble Generator Valve RH, Accelerator Pedal Position Sensor Main Signal Waveform
    G10292544Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Tumble generator valve RH motor open (E159) No. 14 (+) - Engine ground 3 (E159) No. 10:
    Tumble generator valve RH motor closed (E159) No. 30 (+) - Engine ground 3 (E159) No. 10:
    Tumble generator valve RH position signal (E158) No. 40 (+) - Engine ground 3 (E159) No. 10:
    Accelerator pedal position sensor main signal (B134) No. 17 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition (a) accelerator pedal fully closed (b) accelerator pedal fully opened
  6. Waveform 6
    Fig 7: Tumble Generator Valve LH, Accelerator Pedal Position Sensor Main Signal Waveform
    G10292545Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Tumble generator valve LH motor open (E159) No. 6 (+) - Engine ground 3 (E159) No. 10:
    Tumble generator valve LH motor closed (E159) No. 22 (+) - Engine ground 3 (E159) No. 10:
    Tumble generator valve LH position signal (E158) No. 41 (+) - Engine ground 3 (E159) No. 10:
    Accelerator pedal position sensor main signal (B134) No. 17 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition (a) accelerator pedal fully closed (b) accelerator pedal fully opened
  7. Waveform 7
    Fig 8: Intake Oil Control Solenoid Valve, Exhaust Oil Control Solenoid Waveform
    G10292546Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Intake oil control solenoid RH (E159) No. 7 (+) - Engine ground 3 (E159) No. 10:
    Intake oil control solenoid LH (E159) No. 15 (+) - Engine ground 3 (E159) No. 10:
    Exhaust oil control solenoid RH (E159) No. 23 (+) - Engine ground 3 (E159) No. 10:
    Exhaust oil control solenoid LH (E159) No. 31 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition While engine idling
  8. Waveform 8
    Fig 9: Fuel Pump Control Unit (Control Signal) Waveform
    G10292547Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Fuel pump control unit (control signal) (B134) No. 40 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition While engine idling
  9. Waveform 9
    Fig 10: Canister Purge Control Solenoid Valve Waveform
    G10292548Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Canister purge control solenoid valve 1 (E159) No. 4 (+) - Engine ground 3 (E159) No. 10:
    Canister purge control solenoid valve 2 (E159) No. 12 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition Actuator ON drive
  10. Waveform 10
    Fig 11: Crankshaft Position Sensor And Ignition Control Waveform
    G10292549Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Crankshaft position sensor (E158) No. 19 (+) - Engine ground 3 (E159) No. 10:
    Ignition control #1 (E159) No. 8 (+) - Engine ground 3 (E159) No. 10:
    Ignition control #2 (E159) No. 16 (+) - Engine ground 3 (E159) No. 10:
    Ignition control #3 (E159) No. 24 (+) - Engine ground 3 (E159) No. 10:
    Ignition control #4 (E159) No. 32 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition While engine idling
  11. Waveform 11
    Fig 12: Starter Relay Control, Starter Cut Relay Control, Accessory Cut Request And Starter Switch Waveform
    G10292550Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Starter switch (B134) No. 45 (+) - Engine ground 3 (E159) No. 10:
    Accessory cut request (B134) No. 2 (+) - Engine ground 3 (E159) No. 10:
    Starter cut relay control (B134) No. 13 (+) - Engine ground 3 (E159) No. 10:
    Starter cut relay control (B134) No. 14 (+) - Engine ground 3 (E159) No. 10:
    Measuring condition When engine is started
  12. Waveform 12
    Fig 13: Starter Relay Control, Engine Speed Output, Battery Voltage Waveform
    G10292551Courtesy of SUBARU OF AMERICA, INC.
    Measured terminal Starter cut relay control (B134) No. 14 (+) - Engine ground 3 (E159) No. 10:
    Engine speed output (B134) No. 4 (+) - Engine ground 3 (E159) No. 10:
    Battery voltage (battery terminal) (+) - Engine ground 3 (E159) No. 10:
    Measuring condition When engine is started
    Fig 14: Engine Control Module (ECM) I/O Signal - Wiring Diagram (1 Of 4)
    G10267495Courtesy of SUBARU OF AMERICA, INC.
    Fig 15: Engine Control Module (ECM) I/O Signal - Wiring Diagram (2 Of 4)
    G10267496Courtesy of SUBARU OF AMERICA, INC.
    Fig 16: Engine Control Module (ECM) I/O Signal - Wiring Diagram (3 Of 4)
    G10267497Courtesy of SUBARU OF AMERICA, INC.
    Fig 17: Engine Control Module (ECM) I/O Signal - Wiring Diagram (4 Of 4)
    G09480867Courtesy of SUBARU OF AMERICA, INC.
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