DTC P2102: Throttle Actuator "A" Control Motor Circuit Low: Notes

-
DTC detecting condition:

Immediately at fault recognition

Trouble symptom:
- Improper idling
- Poor driving performance
- Engine stalls.
Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>General Description>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Basic Diagnostic Procedure>PROCEDURE .

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. 2 and No. 4 of electronic throttle control relay.
4. Measure the resistance between electronic throttle control relay terminals.
  Terminals
  
  No. 1 - No. 3:
Is the resistance less than 1 Ω?

Yes : Go to 2.

No : Replace the electronic throttle control relay. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ELECTRONIC THROTTLE CONTROL RELAY .
CHECK POWER SUPPLY OF ELECTRONIC THROTTLE CONTROL RELAY .
Measure the voltage between M/B (electronic throttle control relay) terminal and engine ground.

Terminals

No. 1 (+) - Engine ground (-):

No. 2 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes : Go to 3.

No : Repair the following item.
- Open circuit or short circuit to ground in harness between M/B (fuse No. 19) and M/B (electronic throttle control relay) terminal
- Blown out of fuse
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY CONNECTOR (SHORT TO POWER SUPPLY) .
1. Disconnect the connector from ECM.
2. Turn the ignition switch to ON.
3. Measure the voltage between M/B (electronic throttle control relay) terminal and engine ground.
  Terminals
  
  No. 4 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes : Repair the short circuit to power in the harness between ECM connector and M/B (electronic throttle control relay) terminal.

No : Go to 4.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY (SHORT TO GROUND) .
1. Turn the ignition switch to OFF.
2. Measure the resistance between M/B (electronic throttle control relay) terminal and engine ground.
  Terminals
  
  No. 3 - Engine ground:
  
  No. 4 - Engine ground:
Is the resistance 1 MΩ or more?

Yes : Go to 5.

No : Repair the short circuit to ground in the harness between ECM connector and M/B (electronic throttle control relay) terminal.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL RELAY (OPEN) .
Measure the resistance between ECM connector and M/B (electronic throttle control relay) terminal.

Connector & terminal

(B134) No. 65 - No. 3:

(B134) No. 36 - No. 4:

Is the resistance less than 1 Ω?

Yes : Repair the poor contact of ECM connector.

No : Repair the open circuit in harness between ECM connector and electronic throttle control relay connector.