P2123
2AZ-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
CAUTION / NOTICE / HINT
HINT: These DTCs relate to the Accelerator Pedal Position (APP) sensor.
DESCRIPTION
HINT:
- This Electronic Throttle Control System (ETCS) does not use a throttle cable.
- This description is for the accelerator pedal position sensor.
HINT: The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor has 2 sensor elements/signal outputs: VPA1 and VPA2. VPA1 is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA1. Voltage applied to VPA1 and VPA2 changes between 0 V and 5 V in proportion to the accelerator pedal angle.
The ECM monitors the accelerator pedal angle from VPA1 and VPA2 signal output, and controls the throttle motor based on these signals.
HINT: After confirming DTCs P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use Techstream to confirm the accelerator pedal position sensor output voltage.
MONITOR DESCRIPTION
When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages 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 output voltage of VPA drops below 0.4 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 circuits 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 help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
1. READ VALUE USING TECHSTREAM (ACCEL POS #1 AND ACCEL POS #2)
(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 / ETCS / Accelerator Position No. 1 and Accelerator Position No. 2.
(d) Read the value displayed on the tester.
Standard voltage:
OK -- CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)
NG -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
(a) Disconnect the Accelerator Pedal Position (APP) sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
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.
3. CHECK ECM (VCPA AND VCP2 VOLTAGE)
(a) Disconnect the APP sensor connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(d) Reconnect the APP sensor connector.
NG -- REPLACE ECM
OK -- Continue to next step.
4. REPLACE ACCELERATOR PEDAL ASSEMBLY
NEXT -- Continue to next step.
5. 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 the DTCs (DTC Check / Clear).
(d) Start the engine.
(e) Allow the engine to idle for 15 seconds.
(f) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(g) Read the DTCs.
Result:
B -- SYSTEM OK
A -- REPLACE ECM