DTC P2123-00; App Sensor No. 1 Circuit High Input: Notes

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DETECTION CONDITION AND POSSIBLE CAUSE

DTC P2123:00	APP sensor No. 1 circuit high input
DETECTION CONDITION	The PCM monitors the input voltage from APP sensor No. 1. If the input voltage at the PCM terminal 2AN is above 4.9 V, the PCM determines that the APP sensor No. 1 circuit input voltage is high. Diagnostic support note This is a continuous monitor (CCM). The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	Regulates the upper limit of the APP sensor output.
POSSIBLE CAUSE	APP sensor connector or terminals malfunction PCM connector or terminals malfunction APP sensor No. 1 malfunction Short to power supply in wiring harness between APP sensor terminal B and PCM terminal 2AN Open circuit in wiring harness between APP sensor terminal C and PCM terminal 2AO PCM malfunction

CAUTION:

Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

PID DESCRIPTION

Item (definition)	Unit/Condition	Definition	Condition/Specification (Reference)
APP1	%	Accelerator pedal opening angle (absolute value) input from APP sensor No. 1	Accelerator pedal released: Approx. 15% Accelerator pedal fully depressed: Approx. 82%
APP1	V	APP sensor No. 1 voltage	Accelerator pedal released: Approx. 0.75 V Accelerator pedal fully depressed: Approx. 4.1 V
APP2	%	Accelerator pedal opening angle (absolute value) input from APP sensor No. 2	Accelerator pedal released: Approx. 7.45% Accelerator pedal fully depressed: Approx. 41%
APP2	V	APP sensor No. 2 voltage	Accelerator pedal released: Approx. 0.38 V Accelerator pedal fully depressed: Approx. 2.05 V