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DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT LOW INPUT

DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT LOW INPUT

DTC DETECTING CONDITION:


• Immediately at fault recognition

• GENERAL DESCRIPTION


TROUBLE SYMPTOM:


• Erroneous idling

• Engine stalls.

• Poor driving performance


Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .


WIRING DIAGRAM:


CHECK CURRENT DATA.

Start the engine.

Read the data of throttle position sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.


Is the voltage less than 0.15 V?

Yes


No

• Even if malfunction indicator light lights up, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector may be the cause.

•
Note

In this case, repair the following:

• Poor contact in throttle position sensor connector

• Poor contact in ECM connector

• Poor contact in coupling connector



CHECK INPUT SIGNAL FOR ECM.

Measure the voltage between ECM connector and chassis ground while throttle valve is fully closed.

Connector & terminal

(B135) No. 9 (+) — Chassis ground (−):

Is the voltage more than 4.5 V?

Yes


No


CHECK INPUT SIGNAL FOR ECM.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 9 (+) — Chassis ground (−):

Shake the ECM harness and connector, while monitoring value of voltage meter. Does the voltage change?

Yes

Repair the poor contact in ECM connector.


No

Contact Service Center.


CHECK INPUT SIGNAL FOR ECM.

Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 7 (+) — Chassis ground (−):

Is the voltage less than 0.15 V?

Yes


No


CHECK INPUT SIGNAL FOR ECM. (USING Vehicle Diagnostic Interface)

Measure the voltage between ECM connector and chassis ground.

Shake the ECM harness and connector, while monitoring value of Vehicle Diagnostic Interface. Does the voltage change?

Yes

Repair the poor contact in ECM connector.


No


CHECK HARNESS BETWEEN ECM AND THROTTLE POSITION SENSOR CONNECTOR.

Turn the ignition switch to OFF.

Disconnect the connectors from throttle position sensor.

Turn the ignition switch to ON.

Measure the voltage between throttle position sensor connector and engine ground.

Connector & terminal

(E13) No. 1 (+) — Engine ground (−):

Is the voltage more than 4.5 V?

Yes


No

• Repair the harness and connector.

•
Note

In this case, repair the following:

• Open circuit in harness between throttle position sensor and ECM connector

• Poor contact in throttle position sensor connector

• Poor contact in ECM connector

• Poor contact in coupling connector

• Poor contact in joint connector



CHECK HARNESS BETWEEN ECM AND THROTTLE POSITION SENSOR CONNECTOR.

Turn the ignition switch to OFF.

Measure the resistance of harness between ECM connector and throttle position sensor connector.

Connector & terminal

(B135) No. 7 — (E13) No. 3:

Is the resistance less than 1 Ω?

Yes


No

• Repair the harness and connector.

•
Note

In this case, repair the following:

• Open circuit in harness between throttle position sensor and ECM connector

• Poor contact in ECM connector

• Poor contact in throttle position sensor connector

• Poor contact in coupling connector



CHECK HARNESS BETWEEN ECM AND THROTTLE POSITION SENSOR CONNECTOR.

Measure the resistance of harness between throttle position sensor connector and engine ground.

Connector & terminal

(E13) No. 3 — Engine ground:

Is the resistance more than 1 MΩ?

Yes


No

Repair the ground short circuit in harness between throttle position sensor and ECM connector.


CHECK POOR CONTACT.

Check poor contact in throttle position sensor connector.

Is there poor contact in throttle position sensor connector?

Yes

Repair the poor contact in throttle position sensor connector.


No

Replace the throttle position sensor.