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, tight corner braking phenomenon.
WIRING DIAGRAM:
CHECK ENGINE GROUND TERMINALS.
Have engine ground terminals been tightened?
| Yes |
| No |
Tighten the engine ground terminals.
CHECK GROUND CIRCUIT OF ECM.
Turn the ignition switch to OFF.Disconnect the connector from ECM.
Measure the resistance of harness between ECM and engine ground.
Connector & terminal
(B134) No. 7 — Engine ground:
(B134) No. 15 — Engine ground:
(B134) No. 22 — Engine ground:
(B137) No. 8 — Engine ground:
(B137) No. 17 — Engine ground:
(B137) No. 18 — Engine ground:
(B84) No. 8 — Engine ground:
(B84) No. 9 — Engine ground:
Is the resistance less than 5 Ω?
| Yes |
| No |
Repair the open circuit in harness between ECM connector and engine grounding terminal.
CHECK THROTTLE POSITION SENSOR.
Disconnect the connector from throttle position sensor.Measure the resistance between throttle position sensor connector receptacle’s terminals.
Terminals
No. 1 — No. 2:
Is the resistance 3.0 — 4.2 kΩ?
| Yes |
| No |
Replace the throttle position sensor.
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?
| Yes |
| No |
Replace the throttle position sensor.
CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR.
Disconnect the connector from TCM.Measure the resistance of harness between TCM and throttle position sensor connector.
Connector & terminal
(B54) No. 3 — (E13) No. 3:
Is the resistance less than 1 Ω?
| Yes |
| No |
Repair the open circuit in harness between TCM and throttle position sensor connector, and poor contact in coupling connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between TCM and throttle position sensor connector.Connector & terminal
(B54) No. 2 — (E13) No. 1:
Is the resistance less than 1 Ω?
| Yes |
| No |
Repair the open circuit in harness between TCM and throttle position sensor connector, and poor contact in coupling connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between TCM connector and chassis ground.Connector & terminal
(B54) No. 3 — Chassis ground:
Is the resistance more than 1 MΩ?
| Yes |
| No |
Repair the short circuit in harness between TCM and throttle position sensor connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between TCM connector and chassis ground.Connector & terminal
(B54) No. 2 — Chassis ground:
Is the resistance more than 1 MΩ?
| Yes |
| No |
Repair the short circuit in harness between TCM and throttle position sensor connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure the resistance of harness between TCM and ECM connector.Connector & terminal
(B54) No. 3 — (B135) No. 7:
Is the resistance less than 1 Ω?
| Yes |
| No |
Repair the open circuit in harness between TCM and ECM connector.
CHECK HARNESS CONNECTOR BETWEEN TCM AND ECM.
Measure the resistance of harness between TCM and ECM connector.Connector & terminal
(B54) No. 2 — (B135) No. 9:
Is the resistance less than 1 Ω?
| Yes |
| No |
Repair the open circuit in harness between TCM and ECM connector.
CHECK INPUT SIGNAL FOR TCM USING Vehicle Diagnostic Interface.
Connect the connectors to TCM, throttle position sensor and ECM.Connect the Vehicle Diagnostic Interface to data link connector.
Turn the ignition switch to ON (engine OFF).
Turn the Vehicle Diagnostic Interface switch to ON.
Throttle fully closed.
Read the data of throttle position sensor using Vehicle Diagnostic Interface.
| • | Throttle
position sensor input signal is indicated. | |
Is the value voltage 0.2 — 1.0 V?
| Yes |
| No |
CHECK INPUT SIGNAL FOR TCM USING Vehicle Diagnostic Interface.
Throttle fully open.| Note | ||
Must be changed correspondingly with the accelerator pedal operation (from “released” to “depressed” position). |
Is the value voltage 4.2 — 4.7 V?
| Yes |
| No |
CHECK INPUT SIGNAL FOR TCM USING Vehicle Diagnostic Interface (THROTTLE POSITION SENSOR POWER SUPPLY).
Read the data of throttle position sensor power supply using Vehicle Diagnostic Interface.| • | Throttle
position sensor power supply voltage is indicated. | |
Is the value voltage 4.8 — 5.3 V?
| Yes |
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.
| No |
CHECK POOR CONTACT.
Is there poor contact in throttle position sensor circuit?
| Yes |
Repair the poor contact.
| No |
Replace the TCM.