DTC P2101: Throttle Actuator "A" Control Motor Circuit Range/Performance: Notes

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Poor driving performance
Engine stalls.

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>CLEAR MEMORY MODE>OPERATION ., and inspection mode. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>INSPECTION MODE>PROCEDURE .
Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System. Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK ELECTRONIC THROTTLE CONTROL RELAY.
1. Turn the ignition switch to OFF.
2. Remove the electronic throttle control relay.
3. Connect the battery to terminals No. 16 and No. 17 of electronic throttle control relay.
4. Measure the resistance between electronic throttle control relay terminals.
Terminals

No. 14 - No. 15:

Is the resistance less than 1 Ω?

Yes: Go to 2.

No: Replace the electronic throttle control relay. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>ELECTRONIC THROTTLE CONTROL RELAY .
CHECK POWER SUPPLY OF ELECTRONIC THROTTLE CONTROL RELAY.
Measure the voltage between electronic throttle control relay connector and chassis ground.

Connector & terminal

(B225) No. 15 (+) - Chassis ground (-):

Is the voltage 10 V or more?

Yes: Go to 3.

No: Repair the open or short to ground in the power supply circuit.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY CONNECTOR.
1. Disconnect the connector from ECM.
2. Turn the ignition switch to ON.
3. Measure the voltage between electronic throttle control relay connector and chassis ground.
  Connector & terminal
  
  (B225) No. 17 (+) - Chassis ground (-):
Is the voltage 10 V or more?

Yes: Repair the short circuit to power in the harness between ECM connector and electronic throttle control relay connector.

No: Go to 4.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY CONNECTOR.
1. Turn the ignition switch to OFF.
2. Measure the resistance between electronic throttle control relay connector and chassis ground.
  Connector & terminal
  
  (B225) No. 14 - Chassis ground:
  
  (B225) No. 17 - Chassis ground:
Is the resistance 1 MΩ or more?

Yes: Go to 5.

No: Repair the short circuit to ground in harness between ECM connector and electronic throttle control relay connector.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY CONNECTOR.
Measure the resistance between ECM connector and electronic throttle control relay connector.

Connector & terminal

(B134) No. 39 - (B225) No. 17:

(B134) No. 11 - (B225) No. 14:

Is the resistance less than 1 Ω?

Yes: Go to 6.

No: Repair the open circuit in harness between ECM connector and electronic throttle control relay connector.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connectors from electronic throttle control.
3. Measure the resistance between the ECM connector and engine ground.
  Connector & terminal
  
  (E158) No. 18 - Engine ground:
  
  (E158) No. 17 - Engine ground:
  
  (E158) No. 29 - Engine ground:
Is the resistance 1 MΩ or more?

Yes: Go to 7.

No: Repair the ground short circuit of harness between ECM connector and electronic throttle control connector.
CHECK SHORT CIRCUIT INSIDE THE ECM.
1. Connect the connector to ECM.
2. Measure the resistance between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 1 - Engine ground:
  
  (E57) No. 4 - Engine ground:
Is the resistance 220 kΩ or more?

Yes: Go to 8.

No: Repair the ground short circuit of harness between ECM connector and electronic throttle control connector. Replace the ECM if defective. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>ENGINE CONTROL MODULE (ECM) .
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR.
1. Disconnect the connector from ECM.
2. Measure the resistance of harness between ECM connector and electronic throttle control connector.
  Connector & terminal
  
  (E158) No. 17 - (E57) No. 1:
  
  (E158) No. 30 - (E57) No. 3:
  
  (E158) No. 29 - (E57) No. 4:
Is the resistance less than 1 Ω?

Yes: Go to 9.

No: Repair the open circuit of harness between ECM connector and electronic throttle control connector.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR.
1. Connect the connector to ECM.
2. Measure the resistance between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 3 - Engine ground:
Is the resistance less than 5 Ω?

Yes: Go to 10.

No: Repair the harness and connector.
NOTE:
In this case, repair the following item:
- Open circuit of harness between ECM connector and engine ground
- Poor contact of ECM connector
- Poor contact of coupling connector
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR.
1. Turn the ignition switch to ON.
2. Measure the voltage between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 1 (+) - Engine ground (-):
  
  (E57) No. 4 (+) - Engine ground (-):
Is the voltage 5 V or more?

Yes: Repair the short circuit to power in the harness between ECM connector and electronic throttle control connector.

No: Go to 11.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between ECM connectors.
  Connector & terminal
  
  (E158) No. 18 - (E158) No. 17:
  
  (E158) No. 18 - (E158) No. 29:
Is the resistance 1 MΩ or more?

Yes: Go to 12.

No: Repair the short circuit to power in the harness between ECM connector and electronic throttle control connector.
CHECK SENSOR OUTPUT.
1. Connect all connectors.
2. Start the engine and warm up completely.
3. Stop the engine, and then turn the ignition switch to ON (engine OFF).
4. Read the value of «Main-Throttle Sensor» using Subaru Select Monitor.
NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (W/O STI)>SUBARU SELECT MONITOR .

Is the value of «Main-Throttle Sensor» 0.60 - 0.65 V?

Yes: Go to 13.

No: Repair the poor contact of electronic throttle control connector. Replace the electronic throttle control if defective. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>THROTTLE BODY .
CHECK SENSOR OUTPUT.
Read the value of «Sub-Throttle Sensor» using Subaru Select Monitor.

NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (W/O STI)>SUBARU SELECT MONITOR .

Is the value of «Sub-Throttle Sensor» 0.60 - 0.65 V?

Yes: Go to 14.

No: Repair the poor contact of electronic throttle control connector. Replace the electronic throttle control if defective. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>THROTTLE BODY .
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL MOTOR.
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 between ECM connector and electronic throttle control connector.
  Connector & terminal
  
  (E159) No. 1 - (E57) No. 5:
  
  (E159) No. 2 - (E57) No. 6:
Is the resistance less than 1 Ω?

Yes: Go to 15.

No: Repair the open circuit of harness between ECM connector and electronic throttle control.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL MOTOR.
1. Connect the connector to ECM.
2. Turn the ignition switch to ON.
3. Measure the voltage between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 5 (+) - Engine ground (-):
  
  (E57) No. 6 (+) - Engine ground (-):
Is the voltage 5 V or more?

Yes: Repair the short circuit to power in the harness between ECM connector and electronic throttle control connector.

No: Go to 16.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL MOTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between electronic throttle control connector and engine ground.
  Connector & terminal
  
  (E57) No. 5 - Engine ground:
  
  (E57) No. 6 - Engine ground:
Is the resistance 1 MΩ or more?

Yes: Go to 17.

No: Repair the ground short circuit of harness between ECM connector and electronic throttle control connector.
CHECK ELECTRONIC THROTTLE CONTROL MOTOR HARNESS.
Measure the resistance between electronic throttle control connectors.

Connector & terminal

(E57) No. 5 - (E57) No. 6:

Is the resistance 1 MΩ or more?

Yes: Go to 18.

No: Repair the short circuit in harness between ECM connector and electronic throttle control connector.
CHECK ELECTRONIC THROTTLE CONTROL GROUND CIRCUIT.
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(B134) No. 35 - Engine ground:

(B134) No. 47 - Engine ground:

(E159) No. 10 - Engine ground:

(E159) No. 17 - Engine ground:

(E159) No. 18 - Engine ground:

(E159) No. 25 - Engine ground:

(E159) No. 26 - Engine ground:

Is the resistance less than 5 Ω?

Yes: Go to 19.

No: Repair the harness and connector.
NOTE:
In this case, repair the following item:
- Open circuit of harness between ECM connector and engine ground
- Poor contact of coupling connector
CHECK ELECTRONIC THROTTLE CONTROL.
Measure the resistance between electronic throttle control terminals.

Terminals

No. 5 - No. 6:

Is the resistance 50 Ω or less?

Yes: Go to 20.

No: Replace the electronic throttle control. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>THROTTLE BODY .
CHECK ELECTRONIC THROTTLE CONTROL.
Move the throttle valve to the fully opened and fully closed positions with fingers.

Check that the valve returns to the specified position when releasing fingers.

Does the valve return to the specified position? Standard value: 3 mm (0.12 in) from fully closed position

Yes: Repair the poor contact of ECM connector.

No: Replace the electronic throttle control. Refer to FUEL INJECTION (FUEL SYSTEMS) (W/O STI)>THROTTLE BODY .