Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2006 Mazda 6 MazdaspeedFACTORY OEM SERVICE PROCEDURE

DTC P2123: Notes

DTC P2123 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P2123

Accelerator pedal position (APP) sensor No. circuit high input

DETECTION CONDITION

The PCM monitors the APP sensor No. signal. If the PCM detects that the APP sensor No. voltage is above 4.5 V , the PCM determines that the APP sensor No. circuit has a malfunction.

Diagnostic support note

This is a continuous monitor (CCM).
MIL illuminates if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA is available.
DTCs are stored in the PCM memory.

POSSIBLE CAUSE

APP sensor malfunction
Connector or terminal malfunction
Open circuit between APP sensor terminal E and PCM terminal 3A
Open circuit between APP sensor terminal F and PCM terminal 3D
Short to constant voltage in the supply circuit between APP sensor terminal F and PCM terminal 3D

Courtesy of MAZDA MOTORS CORP.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready Tools Compare Repair Quote Quote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.