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

1. -

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Poor driving performance
Engine stall

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. 20) 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

(B61) No. 65 - No. 3:

(B61) 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.