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Home >> Subaru >> 2017 >> Forester 2.0XT Touring >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics - Introduction) (H4DOTC) >> Engine Control Module (ECM) I/O Signal >> Electrical Specification
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Electrical Specification

Fig 1: Identifying Engine Control Module Connector Terminals
G10409858Courtesy 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 *1: Waveform
Ground E158 31 0 0 -
Intake camshaft position sensor LH E158 21 0 or 5 0 or 5 *1: Waveform
Intake camshaft position sensor RH E158 20 0 or 5 0 or 5 *1: Waveform
Exhaust camshaft position sensor LH E158 33 0 or 5 0 or 5 *1: Waveform
Exhaust camshaft position sensor RH E158 32 0 or 5 0 or 5 *1: Waveform
Camshaft position sensor ground E158 34 0 0 -
Front oxygen (A/F) sensor IP (+) signal E158 15 1.7 3.3 Waveform
VS (+) signal E158 27 2.2 4 Waveform
COM signal E158 39 9.8 3.6 Waveform
Heater signal E159 9 Battery voltage 0 or battery voltage Waveform
Rear oxygen sensor Signal (+) E158 16 0.3 0.1 - 0.9 Waveform
Signal (-) E158 42 2 2 -
Heater signal E159 3 Battery voltage 0 or battery voltage Waveform
Air flow sensor Signal B134 16 0.3 1.2 -
Ground B134 28 0 0 -
Intake air temperature sensor (integrated with air flow sensor) E158 5 2.7 3 -
Engine coolant temperature sensor E158 38 2.7 1.8 -
Engine oil temperature sensor E158 2 2.9 2.1 -
Manifold absolute pressure sensor E158 4 1.9 0.8 -
Intake air temperature sensor (integrated with manifold absolute pressure sensor) E158 25 3 3 -
Fuel pressure sensor E158 6 2 1 -
Knock sensor 1 E158 14 2.5 2.5 Waveform
Knock sensor 2 E158 26 2.5 2.5 Waveform
Battery temperature sensor B134 41 2.2 2.1 -
Battery current sensor B134 42 2.7 2.1 -
Accelerator pedal position sensor Main power supply B134 30 5 5 -
Main signal B134 17 Fully closed: 0.4 - 1
Fully open: 2.4 - 3.7		 Fully closed: 0.4 - 1
Fully open: 2.4 - 3.7		 -
Main ground B134 31 0 0 -
Sub signal B134 29 Fully closed: 0.4 - 1
Fully open: 2.4 - 3.7		 Fully closed: 0.4 - 1
Fully open: 2.4 - 3.7		 -
Tumble generator valve actuator RH Position signal E158 40 0.43 - 1.19 Closing direction: 2.38 - 3.93
Opening direction: 0.43 - 1.19		 -
Motor open E159 14 Battery voltage 0 or battery voltage Waveform
Motor closed E159 30 Battery voltage 0 or battery voltage Waveform
Tumble generator valve actuator LH Position signal E158 41 2.38 - 3.93 Closing direction: 0.43 - 1.19 Opening direction: 2.38 - 3.93 -
Motor open E159 6 Battery voltage 0 or battery voltage Waveform
Motor closed E159 22 Battery voltage 0 or battery voltage Waveform
Intake oil control solenoid RH E159 7 Battery voltage 0 or battery voltage Waveform
Intake oil control solenoid LH E159 15 Battery voltage 0 or battery voltage Waveform
Exhaust oil control solenoid RH E159 23 Battery voltage 0 or battery voltage Waveform
Exhaust oil control solenoid LH E159 31 Battery voltage 0 or battery voltage Waveform
Wastegate control solenoid valve E159 11 Battery voltage Battery voltage -
Canister purge control solenoid valve 1 E159 4 Battery voltage 0 or battery voltage Waveform
Canister purge control solenoid valve 2 E159 12 Battery voltage 0 or battery voltage Waveform
Ignition control #1 E159 8 0 0 or 5 Waveform
#2 E159 16 0 0 or 5 Waveform
#3 E159 24 0 0 or 5 Waveform
#4 E159 32 0 0 or 5 Waveform
EGR control valve A+ E159 5 Battery voltage 0 or battery voltage -
A- E159 21 Battery voltage 0 or battery voltage -
B+ E159 13 Battery voltage 0 or battery voltage -
B- E159 29 Battery voltage 0 or battery voltage -
Fuel pump control unit Control signal B134 40 Battery voltage 0 or battery voltage Waveform
Diagnostic signal B134 44 0 Battery voltage -
High-pressure fuel pump (Hi) E158 10 2.4 0 or battery voltage Waveform
High-pressure fuel pump (Lo) E158 22 2.4 0 or battery voltage Waveform
Fuel injector Power supply 1 B134 36 Battery voltage Battery voltage -
Power supply 2 B134 48 Battery voltage Battery voltage -
#1 (+) E158 11 2.4 - Measurement is prohibited while the engine is running.
#1 (-) E158 12 2.4 -
#2 (+) E158 23 2.4 -
#2 (-) E158 24 2.4 -
#3 (+) E158 35 2.4 -
#3 (-) E158 36 2.4 -
#4 (+) E158 47 2.4 -
#4 (-) E158 48 2.4 -
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 0 or battery voltage -
Electronic throttle control motor (-) E159 1 0 0 or battery voltage -
Electronic throttle relay control B134 39 0 0 -
Starter relay control B134 14 2.9 2.9 -
Self-shutoff relay control B134 38 0 0 -
Starter cut relay control B134 13 0 0 Model with push button start
Main fan relay control B134 37 Battery voltage 0 or battery voltage -
Sub fan relay control B134 25 Battery voltage 0 or battery voltage -
A/C relay control B134 1 Battery voltage 0 or battery voltage -
A/C switch B134 21 ON: Battery voltage OFF: 0 ON: Battery voltage OFF: 0 Manual A/C model
Blower fan switch B134 22 ON: 0 OFF: Battery voltage ON: 0 OFF: Battery voltage Manual A/C model
Starter switch B134 45 0 0 Model with push button start Cranking: Waveform
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 -
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 Battery voltage Battery voltage Model with push button start Cranking: 0
Engine speed output B134 4 Battery voltage 0 or battery voltage Model with push button start Waveform
Generator control B134 26 1.8 1.8 -
CAN (Hi) B134 10 - - -
(Lo) B134 9 - - -
Blow-by leak diagnosis E158 7 0 0 At the time of open circuit (fault): 5
Immobilizer communication E158 43 - - -
Delivery mode switch E158 45 Battery voltage Battery voltage -
Control module power supply B134 12 Battery voltage Battery voltage -
B134 24 Battery voltage Battery voltage -
Backup power supply B134 23 Battery voltage Battery voltage -
Sensor power supply B134 18 5 5 -
E159 19 5 5 -
Leak check valve ASSY 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 0.8 - 1.2 1 - 1.6 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 28 0 0 -

Measuring condition: 

NOTE:
  • For measurement of the waveform of the crankshaft position sensor, we recommend using the DST-i oscilloscope function or a general oscilloscope.
  • Perform measurement after warming up the engine.
  • Set the select lever in "P" range or "N" range, or the shift lever in neutral.
  • Turn the A/C to OFF.
  • Turn all the accessory switches to OFF.
  • At idling

*1: Waveform 

Fig 2: Engine Control Module Waveform
G11270493Courtesy of SUBARU OF AMERICA, INC.
Measured terminal Crankshaft position sensor (+) signal (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
Fig 3: Engine Control Module Communication Diagram (1 Of 4)
G11270494Courtesy of SUBARU OF AMERICA, INC.
Fig 4: Engine Control Module Communication Diagram (2 Of 4)
G11270495Courtesy of SUBARU OF AMERICA, INC.
Fig 5: Engine Control Module Communication Diagram (3 Of 4)
G11270496Courtesy of SUBARU OF AMERICA, INC.
Fig 6: Engine Control Module Communication Diagram (4 Of 4)
G09480867Courtesy of SUBARU OF AMERICA, INC.
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