2006 Mazda MX-5 Miata BaseFACTORY OEM SERVICE PROCEDURE

DTC P2123: Notes

DETECTION CONDITION AND POSSIBLE CAUSE (DTC P2123)

DTC P2123 APP sensor No.1 circuit high input
DETECTION CONDITION 
  • The PCM monitors the input voltage from APP sensor No.1 when the engine is running. If the input voltage is above 4.8 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 MIL illuminates if the PCM detects the above malfunction condition during the first drive cycle.
  • PENDING CODE is available if the PCM detects the above malfunction conditions.
  • FREEZE FRAME DATA is available.
  • The DTCs is stored in the PCM memory.
POSSIBLE CAUSE 
  • APP sensor No.1 malfunction
  • Connector or terminal malfunction
  • Short to power supply in wiring harness between APP sensor terminal F and PCM terminal 1AO
  • Open circuit in wiring harness between APP sensor terminal E and PCM terminal 1AS
  • PCM malfunction
G04317739Courtesy 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 ToolsCompare Repair QuoteQuote 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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.