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 P0123: Notes

DTC P0123 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0123

TP sensor No. circuit high input

DETECTION CONDITION

If the PCM detects that the TP sensor No. voltage is above 4.9 V after ignition switch to the ON position, PCM determines that TP circuit has a malfunction.

Diagnostic support note

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

POSSIBLE CAUSE

TP sensor malfunction
Connector or terminal malfunction
Open circuit between throttle body terminal B and PCM terminal 3P
Open circuit between throttle body terminal D and PCM terminal 3Q
Short to the constant voltage supply circuit between throttle body terminal A and PCM terminal 3M

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.