2017 Subaru Legacy 2.5iFACTORY OEM SERVICE PROCEDURE

DTC P0606: Control Module Processor: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

  • Improper idling
  • Poor driving performance
CAUTION:
  • After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to OPERATION , Clear Memory Mode, and Inspection Mode Ref. to PROCEDURE , Inspection Mode.
  • Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram: 

Engine Electrical System Ref. to WIRING DIAGRAM , Engine Electrical System.

Fig 1: Control Module Processor - Wiring Diagram
G11583425Courtesy of SUBARU OF AMERICA, INC.
Step Check Yes No
1 CHECK INPUT VOLTAGE OF ECM. 
  1. Turn the ignition switch to ON.
  2. Measure the voltage between ECM connector and chassis ground.

Connector & terminal 
(B134) No. 14 (+) - Chassis ground (-): 
(B134) No. 1 (+) - Chassis ground (-): 		 Is the voltage 10 - 13 V? Go to step 2  Repair the open or short to ground in the power supply circuit.
2 CHECK INPUT VOLTAGE OF ECM. 
  1. Start the engine.
  2. Measure the voltage between ECM connector and chassis ground.

Connector & terminal 
(B134) No. 14 (+) - Chassis ground (-): 
(B134) No. 1 (+) - Chassis ground (-): 		 Is the voltage 13 - 15 V? Go to step 3  Repair the open or short to ground in the power supply circuit.
3 CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connector from ECM.
  3. Disconnect the connectors from electronic throttle control.
  4. Measure the resistance of harness between ECM connector and electronic throttle control connector.

Connector & terminal 
(E158) No. 32 - (E57) No. 5: 
(E158) No. 34 - (E57) No. 3: 		 Is the resistance less than 1 Ω? Go to step 4  Repair the open circuit of harness between ECM connector and electronic throttle control connector.
4 CHECK ECM GROUND HARNESS. 
  1. Connect all connectors.
  2. Turn the ignition to ON.
  3. Measure the voltage between ECM connector and chassis ground.

Connector & terminal 
(E158) No. 61 (+) - Chassis ground (-): 
(E158) No. 62 (+) - Chassis ground (-): 
(E158) No. 63 (+) - Chassis ground (-): 
(E158) No. 64 (+) - Chassis ground (-): 
(E158) No. 65 (+) - Chassis ground (-): 		 Is the voltage less than 1 V? Check the connector for poor contact and check the harness. Replace the ECM if no fault is found. Ref. to ENGINE CONTROL MODULE (ECM) Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in ground circuit
  • Loose engine ground terminal
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.