Transmission Control Systems

TROUBLE CODE 31
THROTTLE POSITION SENSOR

Diagnosis
Input signal circuit of Throttle Position Sensor is open or shorted.

Trouble Symptom
Shift point too high or too low; Engine brake not effected in "3" range; excessive shift shock; excessive tight corner "braking".





1. Measure signal voltage input of Transmission Control Module (TCM).
a. Turn Ignition Switch "ON" (with Engine "OFF").





b. Measure signal voltage input emitted from Throttle Position Sensor with Accelerator Pedal fully depressed.

Connector & Terminal / Specified Voltage:
(B53) No. 20 - (B52) No. 14 /
3.3 - 0.7 Volts (Throttle fully closed.)
3.9 - 4.3 Volts (Throttle fully open.)

Select Monitor Function Mode
- Mode: F09
- Condition:
Ignition Switch "ON" (Engine "OFF").
- Specified Data:
THV F09
0.3 - 0.7 Volts (Throttle fully closed.)
0.9 - 4.3 Volts (Throttle fully open.)
[Must be changed correspondingly with Accelerator Pedal operation (from "released" to "depressed" position)].

2. Check harness and connectors between TCM and Throttle Position Sensor and between TCM and Engine Control Module (ECM) (MFI).
a. Disconnect connector from TCM.
b. Disconnect connector from ECM (MFI).
c. Disconnect connector from Throttle Position Sensor.





d. Measure resistance between TCM and Throttle Position Sensor connectors.

Connector & Terminal / Specified Resistance:
(B53) No. 20 - (E10) No. 2 / 0 Ohms.
(B53) No. 20 - Body / 1 M Ohm, minimum
(B53) No. 1 - (E10) No. 3 / 0 Ohms.
(B53) No. 1 - Body / 1 M Ohm, minimum





e. Measure resistance between TCM and ECM (MFI) connectors.

Connector & Terminal / Specified Resistance:
(B53) No. 1 - (E30) No. 15 / 0 Ohms.

3. Check voltage of power supply line.
a. Turn Ignition Switch "ON" (with Engine "OFF").





b. Measure voltage of Throttle Position Sensor connector.

Connector & Terminal / Specified Voltage:
(E10) No. 3 - No. 1 / 4.8 - 5.7 Volts

Select Monitor Function Mode
- Mode: F14
- Condition:
Ignition Switch "ON" (Engine "OFF")
- Specified Data:
THVCC F14
4.8 - 5.7 Volts
(Throttle Position Sensor power supply voltage is indicated.)

4. Check Throttle Position Sensor.
a. Disconnect connector from Throttle Position Sensor.





b. Measure resistance between Throttle Position Sensor Terminals.

Terminal / Specified Resistance:
(E10) No. 1 - No. 2 /
500 Ohms (Throttle fully closed.)
4 - 4.5 K Ohms (Throttle fully open.)
(E10) No. 1 - No. 3 / 5 K Ohms.