DTC Advanced Diagnostics: P0122, P0123
DTC P0122:Throttle Position (TP) Sensor A Circuit Low Voltage
DTC P0123:Throttle Position (TP) Sensor A Circuit High Voltage

General Description

The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the PGM-FI subrelay circuit, the accelerator pedal position (APP) sensor, and the powertrain control module (PCM). TP sensor A is a semiconductor type, and it is attached to the throttle body and shaft to determine throttle valve position. The throttle valve position signal from TP sensor A is transmitted to the PCM for target position feedback control. If the signal from TP sensor A is a fixed value for a set time, the PCM detects a TP sensor A malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
200 milliseconds or more
DTC Type
One drive cycle, MIL on

Enable Conditions
Condition
 
Vehicle
ON mode

Malfunction Threshold
DTC: P0122

The TP sensor A output voltage [TP SENSOR A] is 0.3 V or less for at least 200 milliseconds.

DTC: P0123

The TP sensor A output voltage [TP SENSOR A] is 4.8 V or more for at least 200 milliseconds.

[ ]: HDS Parameter

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
DTC: P0122
TP sensor A THL1 line short to ground
TP sensor A VCC line open

DTC: P0123
TP sensor A THL1 line open
TP sensor A SG line open

Common
TP sensor A failure
PCM internal circuit failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.