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Home >> Subaru >> 2006 >> Baja Turbo, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 16 (Automatic Transmission Diagnostics (4AT) (H4SO)) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC 31 Throttle Position Sensor

DTC 31 Throttle Position Sensor

WARNING: This page is about a different variant/trim than selected.

DIAGNOSIS: 

The input signal circuit of throttle position sensor is open or shorted.

TROUBLE SYMPTOM: 

Shift point too high or too low; excessive shift shock; excessive tight corner "braking".

WIRING DIAGRAM: 

Fig 1: Throttle Position Sensor - Wiring Diagram
G04990730Courtesy of SUBARU OF AMERICA, INC.
DIAGNOSTIC PROCEDURE CHART

Step Check Yes No
1 CHECK ENGINE GROUND TERMINALS.  Have engine ground terminals been tightened? Go to step 2.  Tighten the engine ground terminals.
2 CHECK GROUND CIRCUIT OF ECM. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connector from ECM.
  3. Measure the resistance of harness between ECM and engine ground.

    Connector & terminal 

    (B134) No. 7 - Engine ground: 

    (B134) No. 35 - Engine ground: 

    (B136) No. 5 - Engine ground: 

    (B136) No. 16 - Engine ground: 

    (B136) No. 26 - Engine ground: 

    (B135) No. 21 - Engine ground: 

    (B137) No. 14 - Engine ground: 

 Is the resistance less than 5 Ω? Go to step 3.  Repair the open circuit in harness between ECM connector and engine grounding terminal.
3 CHECK THROTTLE POSITION SENSOR. 
  1. Disconnect the connector from throttle position sensor.
  2. Measure the resistance between throttle position sensor connector receptacle's terminals.

    Terminals No. 4 - No. 2: 

 Is the resistance 3.0 - 4.2 kΩ? Go to step 4.  Replace the throttle position sensor.
4 CHECK THROTTLE POSITION SENSOR. 
Measure the resistance between throttle position sensor connector receptacle's terminals.
Terminals No. 2 - No. 3: 		 Is the resistance 0.35 - 0.5 kΩ? Go to step 5.  Replace the throttle position sensor.
5 CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 
  1. Disconnect the connector from TCM.
  2. Measure the resistance of harness between TCM and throttle position sensor connector.

    Connector & terminal 

    (B55) No. 2 - (E13) No. 3: 

 Is the resistance less than 1 Ω? Go to step 6.  Repair the open circuit in harness between TCM and throttle position sensor connector, and poor contact in coupling connector.
6 CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 
Measure the resistance of harness between TCM and throttle position sensor connector.
Connector & terminal 
(B55) No. 1 - (E13) No. 4: 		 Is the resistance less than 1 Ω? Go to step 7.  Repair the open circuit in harness between TCM and throttle position sensor connector, and poor contact in coupling connector.
7 CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 
Measure the resistance of harness between TCM connector and chassis ground.
Connector & terminal 
(B55) No. 2 - Chassis ground: 		 Is the resistance more than 1 MΩ? Go to step 8.  Repair the short circuit in harness between TCM and throttle position sensor connector.
8 CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR. 
Measure the resistance of harness between TCM connector and chassis ground.
Connector & terminal 
(B55) No. 1 - Chassis ground: 		 Is the resistance more than 1 MΩ? Go to step 9.  Repair the short circuit in harness between TCM and throttle position sensor connector.
9 CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM. 
Measure the resistance of harness between TCM and ECM connector.
Connector & terminal 
(B55) No. 2 - (B135) No. 13: 		 Is the resistance less than 1 Ω? Go to step 10.  Repair the open circuit in harness between TCM and ECM connector.
10 CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM. 
Measure the resistance of harness between TCM and ECM connector.
Connector & terminal 
(B55) No. 1 - (B135) No. 3: 		 Is the resistance less than 1 Ω? Go to step 11.  Repair the open circuit in harness between TCM and ECM connector.
11 PREPARE SUBARU SELECT MONITOR.  Do you have a Subaru Select Monitor? Go to step 14.  Go to step 12. 
12 CHECK INPUT SIGNAL FOR TCM. 
  1. Connect the connectors to TCM, throttle position sensor and ECM.
  2. Turn the ignition switch to ON (engine OFF).
  3. Close the throttle completely.
  4. Measure the voltage between TCM connector and chassis ground.

    Connector & terminal 

    (B55) No. 2 (+) - Chassis ground (-): 

 Is the voltage 0.2 - 1.0 V? Go to step 13.  Go to step 18. 
13 CHECK INPUT SIGNAL FOR TCM. 
  1. Open the throttle completely and hold it.
  2. Measure the voltage between TCM connector and chassis ground.

    Connector & terminal 

    (B55) No. 2 (+) - Chassis ground (-): 

 Is the voltage 4.2 - 4.7 V? Go to step 16.  Go to step 18. 
14 CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR. 
  1. Connect the connectors to TCM, throttle position sensor and ECM.
  2. Connect the Subaru Select Monitor to data link connector.
  3. Turn the ignition switch to ON (engine OFF).
  4. Turn the Subaru Select Monitor switch to ON.
  5. Throttle fully closed.
  6. Read the data of throttle position sensor using Subaru Select Monitor.

  • Throttle position sensor input signal is indicated.
 Is the value voltage 0.2 - 1.0 V? Go to step 15.  Go to step 18. 
15 CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR. 
Throttle fully open.
NOTE: Depress the accelerator pedal until it touches the stopper.
 Is the value voltage 4.2 - 4.7 V? Go to step 18.  Go to step 17. 
16 CHECK INPUT SIGNAL FOR TCM (THROTTLE POSITION SENSOR POWER SUPPLY). 
Measure the voltage between TCM connector and chassis ground.
Connector & terminal 
(B55) No. 1 (+) - Chassis ground (-): 		 Is the voltage 4.8 - 5.3 V? Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in throttle position sensor circuit. Go to step 18. 
17 CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR (THROTTLE POSITION SENSOR POWER SUPPLY). 
Read the data of throttle position sensor power supply using Subaru Select Monitor.
  • Throttle position sensor power supply voltage is indicated.
 Is the value voltage 4.8 - 5.3 V? Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in throttle position sensor circuit. Go to step 18. 
18 CHECK POOR CONTACT.  Is there poor contact in throttle position sensor circuit? Repair the poor contact. Replace the TCM. < Ref. to TRANSMISSION CONTROL MODULE (TCM) . >
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