Description
Hint:
Refer to dtc p2120 (see page es-282).

Monitor description
When the difference between the output voltages of vpa and vpa2 deviates from the standard, the ecm determines that the accelerator pedal position (app) sensor is malfunctioning. The ecm turns on the mil and the dtc is set.
Monitor strategy

Typical enabling conditions

Typical malfunction thresholds
![]()
Fail-safe
The app sensor has two (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 switches to limp mode. In limp mode, the functioning 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 as being fully closed. In this case, the throttle valve remains 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 stops and the system returns to a normal condition.
Wiring diagram
Refer to dtc p2120 (see page es-286).
Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.

Hint:
If any dtcs other than p2121 are output, troubleshoot those dtcs first.

Standard voltage 


Throttle / pedal position sensor
Oxygen (a/f) sensor signal stuckOpen in stop light switch circuit
Description
The skid control ecu detects the brake operating conditions through a signal
transmitted by the stop light
switch. The skid control ecu incorporates an open circuit detection circuit.
This dtc is set under either of
the following conditions:
An open is detected in the stop lig ...
Driver side satellite sensor bus initialization incomplete
Description
The side airbag sensor lh consists of part including the diagnostic circuit
and the lateral deceleration
sensor.
When the center airbag sensor receives signals from the lateral deceleration
sensor, it determines
whether or not the srs should be activated.
Dtc b1643/81 is ...
Pressure control solenoid "d" performance (shift solenoid valve slt)
Description
The throttle pressure that is applied to the primary regulator valve (which
modulates the line pressure)
causes the solenoid valve slt, under electronic control, to precisely modulate
and generate the line
pressure according to the extent that the accelerator pedal is depr ...