P2138
DTC P2138 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D"/"E" VOLTAGE CORRELATIONHINT: This is the procedure for the accelerator pedal position sensor.
CIRCUIT DESCRIPTION
HINT: This Electronic Throttle Control System (ETCS) does not use a throttle cable.
DTC Detection Condition:
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 change between 0.2 V and 5 V depending on the accelerator pedal angle.
The ECM monitors the accelerator pedal angle from VPA1 and VPA2 signal outputs, and controls the throttle actuator based on these signals.
HINT: After confirming DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use the hand-held tester to confirm the accelerator pedal position sensor output voltage.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
When the voltage output of VPA1 or VPA2 deviates from the standard ranges, or difference between the voltage outputs of the two sensors is less than threshold, the ECM concludes that there is a defect in the accelerator pedal position sensor. The ECM illuminates the MIL and sets a DTC.
Example: When the voltage output of the VPA1 below 0.2 V or exceeds 4.8 V, the ECM sets a DTC.
FAIL-SAFE
The accelerator pedal position sensor has 2 (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and changes to limp mode.In limp mode, the remaining circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue driving.
If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed.In this case, the throttle valve will remain closed as if the engine is idling.
If a "pass" condition is detected and then the ignition switch is turned OFF, the fail-safe operation will stop and the system will return to normal condition.
Wiring Diagram:
Step 1:
Step 2 - 3:
Step 4 - 5:
INSPECTION PROCEDURE
HINT: Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected.When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.
CHECK FOR INTERMITTENT PROBLEMS
HINT: Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the hand-held tester is in check mode. In check mode, the hand-held tester uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.
a. Clear the DTCs
b. Set the check mode
c. Perform a simulation test.
d. Check the connector and terminal
e. Wiggle the harness and the connector