P2123

P2122, P2123 APP Sensor

Component Description

The accelerator pedal position sensor is installed on the upper end of the accelerator pedal assembly. The sensor detects the accelerator position and sends a signal to the ECM.





Accelerator pedal position sensor has two sensors. These sensors are a kind of potentiometers which transform the accelerator pedal position into output voltage, and emit the voltage signal to the ECM. In addition, these sensors detect the opening and closing speed of the accelerator pedal and feed the voltage signals to the ECM. The ECM judges the current opening angle of the accelerator pedal from these signals and controls the throttle control motor based on these signals.

Idle position of the accelerator pedal is determined by the ECM receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine operation such as fuel cut.

On Board Diagnosis Logic

These self-diagnoses have the one trip detection logic.

NOTE:

If DTC P2122 or P2123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to [Power Supply and Ground Circuit Check] P0643.





Fail-Safe Mode

When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.






DTC Confirmation Procedure

NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.

with SDT

1) Start engine and let it idle for 1 second.
2) Check DTC.
3) If DTC is detected, go to "Diagnosis Procedure".

with GST

Follow the procedure "WITH SDT" above.

Diagnosis Procedure

1. CHECK GROUND CONNECTIONS

1 Turn ignition switch OFF.
2 Loosen and retighten two ground screws on the body. Refer to Power Supply and Ground Circuit Check.






OK or NG
OK
GO TO 2.
NG
Repair or replace ground connections.

2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT

1 Disconnect accelerator pedal position (APP) sensor harness connector.





2 Turn ignition switch ON.
3 Check voltage between APP sensor terminal 2 and ground with SDT or tester.











OK or NG
OK
GO TO 3.
NG
Repair open circuit, short to ground or short to power in harness or connectors.

3. CHECK APP SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT

1 Turn ignition switch OFF.
2 Disconnect ECM harness connector.
3 Check harness continuity between APP sensor terminal 4 and ECM terminal 82.
Refer to Wiring Diagram.






4 Also check harness for short to ground and short to power.

OK or NG
OK
GO TO 4.
NG
Repair open circuit, short to ground or short to power in harness or connectors.

4. CHECK APP SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1 Check harness continuity between ECM terminal 106 and APP sensor terminal 3.
Refer to Wiring Diagram.






2 Also check harness for short to ground and short to power.

OK or NG
OK
GO TO 5.
NG
Repair open circuit, short to ground or short to power in harness or connectors.

5. CHECK APP SENSOR

Refer to "Component Inspection".

OK or NG
OK
GO TO 7.
NG
GO TO 6.

6. REPLACE ACCELERATOR PEDAL ASSEMBLY

1 Replace accelerator pedal assembly. Refer to [Accelerator Control System: Component] Component.
2 Perform [Accelerator Pedal Released Position Learning] Testing and Inspection.
3 Perform [Throttle Valve Closed Position Learning] Throttle Valve Closed Position Learning.
4 Perform [Idle Air Volume Learning] Idle Air Volume Learning.


INSPECTION END

7. CHECK INTERMITTENT INCIDENT

Refer to [Service Information for Electrical Incident: Intermittent Incident] Service Information for Electrical Incident: Intermittent Incident.


INSPECTION END

Component Inspection

Accelerator Pedal Position Sensor

1) Reconnect all harness connectors disconnected.
2) Turn ignition switch ON.
3) Check voltage between ECM terminals 106 (APP sensor 1 signal), 98 (APP sensor 2 signal) and ground under the following conditions.











4) If NG, replace accelerator pedal assembly and go to the next step.
5) Perform [Accelerator Pedal Released Position Learning] Testing and Inspection.
6) Perform [Throttle Valve Closed Position Learning] Throttle Valve Closed Position Learning.
7) Perform [Idle Air Volume Learning] Idle Air Volume Learning.