Diesel Data: Automotive Repair

Advanced Diagnostics

Advanced Diagnostics - DTC P2135: Throttle Position (TP) Sensor A/B Incorrect Voltage Correlation (Engine Type: K24Z7)

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 electronic throttle control system (ETCS) control relay, the accelerator pedal position (APP) sensor, and the engine control module (ECM). When the accelerator pedal is pressed, the APP sensor detects the accelerator pedal opening value. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the ECM to compute the target position. The ECM then operates the throttle actuator to move the throttle valve to the target position. The actual throttle valve position is determined by TP sensor A (installed in the throttle body). The ECM compares the voltages and the throttle valve positions of TP sensor A and TP sensor B. If the difference of the throttle valve positions is a certain value for a set time, the ECM detects a malfunction in the relationship between TP sensor A and TP sensor B, and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The difference between the throttle valve positions that TP sensor A and TP sensor B determined exceeds the value shown in this table for at least 200 milliseconds.






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.

- TP sensor A/B failure
- TP sensor A TH_1 line short to TP sensor B TH_2 line
- ECM 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 ECM 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 battery.