2012 Subaru Legacy GT LimitedFACTORY OEM SERVICE PROCEDURE

Electrical Specification

Fig 1: Identifying Engine Control Module (ECM) I/O Signal
G05334606Courtesy of SUBARU OF AMERICA, INC.
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 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 -
Shield B136 9 0 0 -
Rear oxygen sensor Signal B136 20 0 0 - 0.9 -
Shield B136 9 0 0 -
Ground (sensor) B135 30 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 0 - 13 - Waveform
Engine coolant temperature sensor Signal B137 22 1.0 - 1.4 1.0 - 1.4 After engine is warmed up.
Ground (sensor) B134 29 0 0 After engine is warmed up.
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 10 - 13 0 or 12 - 14 Waveform
Starter switch B136 16 0 0 Cranking: 8 - 14
Ignition switch B136 30 10 - 13 12 - 14 -
Neutral position switch B136 35 ON: 0 OFF: 10 - 13 ON: 0 OFF: 12 - 14 -
Delivery (test) mode switch B136 34 10 - 13 12 - 14 When fuse is installed: 0
Knock sensor Signal B137 2 2.8 2.8 -
Shield B137 8 0 0 -
Back-up power supply B136 2 10 - 13 12 - 14 Ignition switch "OFF": 10 - 13
Control module power supply B137 7 10 - 13 12 - 14 -
B136 1 10 - 13 12 - 14 -
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 10 - 13 1 - 14 Waveform
#2 B134 11 10 - 13 1 - 14 Waveform
#3 B134 12 10 - 13 1 - 14 Waveform
#4 B134 13 10 - 13 1 - 14 Waveform
Fuel pump control unit Control B136 33 0 or 5 0 or 5 Waveform
Diagnostic signal B135 10 0 or 10 - 13 12 - 14 -
Radiator fan relay 1 control B135 12 ON: 0.5 or less ON: 0.5 or less -
OFF: 10 - 13 OFF: 12 - 14
Radiator fan relay 2 control B135 11 ON: 0.5 or less ON: 0.5 or less -
OFF: 10 - 13 OFF: 12 - 14
Malfunction indicator light B135 33 - - Light "ON": 1 or less
Light "OFF": 10 - 14
Engine speed output B135 15 - 0 - 13 or more Waveform
Purge control solenoid valve 1 B137 6 ON: 1 or less ON: 1 or less Waveform
OFF: 10 - 13 OFF: 12 - 14
Purge control solenoid valve 2 B137 15 ON: 1 or less ON: 1 or less Waveform
OFF: 10 - 13 OFF: 12 - 14
Manifold absolute pressure sensor Signal B137 20 1.7 - 2.4 1.1 - 1.6 -
Power supply B134 19 5 5
Ground (sensor) B134 29 0 0
SSM communication B135 14 1 or less ←→ 4 or more 1 or less ←→ 4 or more -
Electronic Throttle Main B134 18 Approx. 0.9 (After engine is warmed up.) Approx. 0.6 - 0.7 (After engine is warmed up.) Fully closed: Approx. 0.6
Fully open: Approx. 4.0
Sub B134 27 Approx. 1.7 (After engine is warmed up.) Approx. 1.5 - 1.6 (After engine is warmed up.) Fully closed: Approx. 1.5
Fully open: Approx. 4.2
Power supply B134 19 5 5 -
Ground (sensor) B134 29 0 0 -
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 10 - 13 12 - 14 -
Electronic throttle control motor relay B135 17 ON: 0 ON: 0 When ignition switch is turned to ON: ON
OFF: 10 - 13 OFF: 12 - 14
Intake oil flow control solenoid valve (LH) Signal (+) B134 17 ON: 10 - 13 ON: 12 - 14 -
OFF: 0 OFF: 0
Signal (-) B134 16 0 0 -
Intake oil flow control solenoid valve (RH) Signal (+) B134 34 ON: 10 - 13 ON: 12 - 14 -
OFF: 0 OFF: 0
Signal (-) B134 27 0 0 -
Exhaust oil flow control solenoid valve (LH) Signal (+) B134 5 ON: 10 - 13 ON: 12 - 14 -
OFF: 0 OFF: 0
Signal (-) B134 14 0 0 -
Exhaust oil flow control solenoid valve (RH) Signal (+) B134 7 ON: 10 - 13 ON: 12 - 14 -
OFF: 0 OFF: 0
Signal (-) B134 15 0 0 -
Intake camshaft position sensor (LH) B137 16 0 or 5 0 or 5 Waveform
Intake camshaft position sensor (RH) B137 24 0 or 5 0 or 5 Waveform
Exhaust camshaft position sensor (LH) B137 29 0 or 5 0 or 5 Waveform
Exhaust camshaft position sensor (RH) B137 23 0 or 5 0 or 5 Waveform
Camshaft position sensor ground B137 30 0 0 -
Accelerator pedal position sensor Main sensor signal B135 23 Fully closed: 1 Fully closed: 1 -
Fully opened: 3.3 Fully opened: 3.3
Shield B136 4 0 0 -
Main power supply B135 21 5 5 -
Ground (main sensor) B135 29 0 0 -
Sub signal sensor B135 31 Fully closed: 1 Fully closed: 1 -
Fully opened: 3.3 Fully opened: 3.3
Sub power supply B135 22 5 5 -
Ground (sub sensor) B135 30 0 0 -
Starter relay B135 26 ON: 0 ON: 0 ON: cranking
OFF: 10 - 13 OFF: 12 - 14
Clutch switch B135 9 When clutch pedal is depressed: 0 When clutch pedal is depressed: 0 -
When clutch pedal is released: 10 - 13 When clutch pedal is released: 12 - 14
Brake switch 1 (brake switch) B136 15 When brake pedal is depressed: 0 When brake pedal is depressed: 0 -
When brake pedal is released: 10 - 13 When brake pedal is released: 12 - 14
Brake switch 2 (stop light switch) B136 3 When brake pedal is depressed: 10 - 13 When brake pedal is depressed: 12 - 14 -
When brake pedal is released: 0 When brake pedal is released: 0
Cruise control command switch B136 12 When operating nothing: 3.5 - 4.5 When operating nothing: 3.5 - 4.5 -
When operating RES/ACC: 2.5 - 3.5 When operating RES/ACC: 2.5 - 3.5
When operating vehicle distance setting: 1.5 - 2.5 When operating vehicle distance setting: 1.5 - 2.5
When operating SET/COAST: 0.5 - 1.5 When operating SET/COAST: 0.5 - 1.5
When operating CANCEL: 0 - 0.5 When operating CANCEL: 0 - 0.5
Cruise control main switch B136 13 ON: 0 ON: 0 -
OFF: 5 OFF: 5
CAN communication (Hi) B136 17 - - -
(Lo) B136 28 - - -
Self-shutoff control B135 13 0 0 -
Power steering oil pressure switch B137 28 10 - 13 ON: 0
OFF: 12 - 14		 -
Oil level switch B136 26 0 0 Oil level LOW: 10 - 14
Tumble generator valve position sensor signal (RH) B137 11 Fully closed: 0.43 - 1.19 Fully closed: 0.43 - 1.19 -
Fully opened: 2.83 - 4.69 Fully opened: 2.83 - 4.69
Tumble generator valve position sensor signal (LH) B137 10 Fully closed: 0.43 - 1.19 Fully closed: 0.43 - 1.19 -
Fully opened: 2.83 - 4.69 Fully opened: 2.83 - 4.69
Tumble generator valve (RH closed) B134 26 0 or 10 - 13 0 or 12 - 14 -
Tumble generator valve (LH closed) B134 24 0 or 10 - 13 0 or 12 - 14 -
Tumble generator valve (RH open) B134 25 0 or 10 - 13 0 or 12 - 14 -
Tumble generator valve (LH open) B134 23 0 or 10 - 13 0 or 12 - 14 -
Immobilizer communication B135 25 - - -
Fuel tank pressure sensor B136 21 2.3 - 2.7 2.3 - 2.7 -
Pressure control solenoid valve B135 3 ON: 1 or less ON: 1 or less -
OFF: 10 - 13 OFF: 12 - 14
Drain valve B135 4 ON: 1 or less ON: 1 or less -
OFF: 10 - 13 OFF: 12 - 14
Fuel temperature sensor B136 23 2.5 - 3.8 2.5 - 3.8 Ambient temperature: 25°C (77°F)
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 -

Input/output name: 

  • Crankshaft position sensor
  • Intake camshaft position sensor RH
  • Intake camshaft position sensor LH
  • Exhaust camshaft position sensor RH
  • Exhaust camshaft position sensor LH

Measuring condition: 

  • After warming-up
  • At idling
    Fig 2: Identifying Engine Control Module (ECM) I/O Signal (At Idling)
    G06647725Courtesy of SUBARU OF AMERICA, INC.
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  • • 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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