P2123
1ZZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2120: Throttle / Pedal Position Sensor / Switch "D" Circuit
DTC P2120 - Throttle / Pedal Position Sensor / Switch "D" Circuit
DTC P2122 - Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
DTC P2123 - Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
DTC P2125 - Throttle / Pedal Position Sensor / Switch "E" Circuit
DTC P2127 - Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
DTC P2128 - Throttle / Pedal Position Sensor / Switch "E" Circuit High Input
DTC P2138 - Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation
DESCRIPTION
HINT: These DTCs relate to the Accelerator Pedal Position (APP) sensor.
This ETCS (Electronic Throttle Control System) does not use a throttle cable.
The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA1 (main) and VPA2 (sub). The voltage, which is applied to terminals VPA1 and VPA2 of the ECM, varies between 0 V and 5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA1 indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA1 circuit and is used to check the APP sensor itself.
The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA1 and VPA2, and controls the throttle actuator according to these signals.
HINT: When any of these DTCs are set, check the APP sensor voltage by selecting the following menu items on the Techstream: Powertrain / Engine and ECT / Data List / ETCS / Accelerator Position No. 1 and Accelerator Position No. 2.
HINT:
- Accelerator pedal positions are expressed as voltages.
- AP denotes for Accelerator Pedal.
MONITOR DESCRIPTION
When either of the voltage outputs of VPA1 or VPA2 deviates from the standard range, or the difference between the voltage outputs of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the APP sensor. The ECM then illuminates the MIL and sets a DTC.
Example:
When the voltage output of VPA1 drops below 0.2 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is set.
If the malfunction is not repaired successfully, a DTC is set 2 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P2120:
P2122:
P2123:
P2125:
P2127:
P2128:
P2138:
COMPONENT OPERATING RANGE
FAIL-SAFE
When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 are set, the ECM enters fail-safe mode. If either of the 2 sensor circuit malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned OFF.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
PROCEDURE
1. READ VALUE OF TECHSTREAM (ACCELERATOR POSITION SENSOR)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Select the following menu items: Powertrain / Engine and ECT / Data List / Accelerator Position No. 1 and Accelerator Position No. 2.
(d) Read the values displayed on the tester.
Standard voltage:
OK -- CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)
NG -- Continue to next step.
2. INSPECT ACCELERATOR PEDAL ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR)
(a) Disconnect the A25 Accelerator Pedal Position (APP) sensor connector.
(b) Measure the resistance between each terminal.
Standard resistance:
(c) Reconnect the APP sensor connector.
NG -- REPLACE ACCELERATOR PEDAL ASSEMBLY
OK -- Continue to next step.
3. INSPECT ECM (VCPA AND VCP2 VOLTAGE)
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage between the terminals of the E6 ECM connector.
Standard voltage:
NG -- REPLACE ECM
OK -- Continue to next step.
4. INSPECT ECM (VPA AND VPA2 VOLTAGE)
(a) Turn the ignition switch to the ON position.
(b) Measure the voltage between the terminals of the E6 ECM connector.
Standard voltage:
OK -- REPLACE ECM
NG -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (ECM - ACCELERATOR PEDAL POSITION SENSOR)
(a) Disconnect the A25 APP sensor connector.
(b) Disconnect the E6 ECM connector.
(c) Check the resistance.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the APP sensor connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester on.
(c) Clear DTCs (DTC Check / Clear).
(d) Allow the engine to idle for 15 seconds.
(e) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(f) Read DTCs.
Result:
B -- CHECK FOR INTERMITTENT PROBLEMS
A -- REPLACE ECM