DTC Advanced Diagnostics: P2127, P2128 (3.0L Engine)

DTC P2127: Accelerator Pedal Position (APP) Sensor B Circuit Low Voltage DTC P2128: Accelerator Pedal Position (APP) Sensor B Circuit High Voltage

General Description

Courtesy of HONDA, U.S.A., INC.

Accelerator pedal position (APP) sensor A is a part of the electronic throttle control system. It is used to convert the position of the accelerator pedal into electrical signals. Based on these signals, the powertrain control module (PCM) controls the throttle actuator so that the throttle position agrees with the accelerator pedal position. The sensor outputs low signal voltage when the accelerator pedal is not pressed and high signal voltage at pressing the accelerator pedal. If the APP sensor output voltage is excessively high or low, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	0.48 second or more
DTC Type	One drive cycle, MIL on

Enable Conditions

Condition
Vehicle	ON mode

Malfunction Threshold

DTC: P2127

The APP sensor B output voltage [APP Sensor B Voltage] is 0.121 V or less for at least 0.48 second.

DTC: P2128

The APP sensor B output voltage [APP Sensor B Voltage] is 2.426 V* 1 (3.97 V)* 2 or more for at least 0.48 second.

*1: USA and Canada models*2: Mexico models[ ]: 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: P2127

APP sensor B APS2 line open
APP sensor B APS2 line short to ground
APP sensor B VCC5 line open
APP sensor B VCC5 line short to ground

DTC: P2128

APP sensor B APS2 line short to power
APP sensor B SG5 line open

Common

APP sensor B failure
PCM internal failure

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.