The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor 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 oper-
ation such as fuel cut.

On Board Diagnosis Logic

INFOID:0000000005273848

These self-diagnoses have the one trip detection logic.

FAIL-SAFE MODE

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

DTC Confirmation Procedure

INFOID:0000000005273849

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1.

Turn ignition switch OFF and wait at least 10 seconds.

Turn ignition switch ON.

Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1.

Start engine and let it idle for 1 second.

Check DTC.

If DTC is detected, go to

EC-828, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000005273850

CHECK GROUND CONNECTIONS

Turn ignition switch OFF.

PBIB1741E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2127
2127

Accelerator pedal posi-
tion sensor 2 circuit low
input

An excessively low voltage from the APP sen-
sor 2 is sent to ECM.

• Harness or connectors

(The APP sensor 2 circuit is open or
shorted.)
(The TP sensor circuit shorted.)

• Accelerator pedal position sensor

(APP sensor 2)

• Electric throttle control actuator

(TP sensor 1 and 2)

P2128
2128

Accelerator pedal posi-
tion sensor 2 circuit high
input

An excessively high voltage from the APP sen-
sor 2 is sent to ECM.

Engine operating condition in fail-safe mode

The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

P2127, P2128 APP SENSOR

EC-829

< COMPONENT DIAGNOSIS >

[VQ40DE]

Loosen and retighten three ground screws on the body, Refer to

EC-549, "Ground Inspection"

OK or NG

>> GO TO 2.

>> Repair or replace ground connections.

CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I

Disconnect accelerator pedal position (APP) sensor harness connector.

Turn ignition switch ON.

Check voltage between APP sensor terminal 1 and ground with
CONSULT-III or tester.

OK or NG

>> GO TO 7.

>> GO TO 3.

CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II

Turn ignition switch OFF.

Disconnect ECM harness connector.

Check harness continuity between APP sensor terminal 1 and ECM terminal 91.
Refer to wiring diagram.

OK or NG

>> GO TO 4.

>> Repair open circuit.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III

Check harness for short to power and short to ground, between the following terminals.

BBIA0539E

Voltage: Approximately 5V

BBIA0556E

PBIB2611E

Continuity should exist.

ECM terminal

Sensor terminal

APP sensor terminal 1

Electric throttle control actuator terminal 2

EC-830

< COMPONENT DIAGNOSIS >

[VQ40DE]

P2127, P2128 APP SENSOR

OK or NG

>> GO TO 5.

>> Repair short to ground or short to power in harness or connectors.

CHECK THROTTLE POSITION SENSOR

Refer to

EC-656, "Component Inspection"

OK or NG

>> GO TO 11.

>> GO TO 6.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

Replace electric throttle control actuator.

Perform

EC-473, "Throttle Valve Closed Position Learning"

Perform

EC-473, "Idle Air Volume Learning"

>> INSPECTION END

CHECK APP SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.

Disconnect ECM harness connector.

Check harness continuity between APP sensor terminal 5 and ECM terminal 83.
Refer to Wiring Diagram.

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

OK or NG

>> GO TO 8.

>> Repair open circuit or short to ground or short to power in harness or connectors.

CHECK APP SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Check harness continuity between ECM terminal 98 and APP sensor terminal 6.
Refer to Wiring Diagram.

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

OK or NG

>> GO TO 9.

>> Repair open circuit or short to ground or short to power in harness or connectors.

CHECK APP SENSOR

Refer to

EC-831, "Component Inspection"

OK or NG

>> GO TO 11.

>> GO TO 10.

10.

REPLACE ACCELERATOR PEDAL ASSEMBLY

Replace accelerator pedal assembly.

Perform

EC-473, "Accelerator Pedal Released Position Learning"

Perform

EC-473, "Throttle Valve Closed Position Learning"

Perform

EC-473, "Idle Air Volume Learning"

>> INSPECTION END

11.

CHECK INTERMITTENT INCIDENT

Refer to

GI-46, "Intermittent Incident"

Continuity should exist.

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