Check Engine Code
P0123
Throttle Position Sensor / Switch A Circuit High Input
Severity: high
DIY difficulty: 2/5
Typical cost: $50–$500
What P0123 means
TPS reading is above the expected WOT voltage. Usually a wiring short to 5V or a failed sensor.
Symptoms
- CEL
- Limp mode
- High idle
- Erratic shifting
Likely causes (most common first)
- Short to 5V reference
- Failed TPS
- Damaged harness
Can I keep driving?
High — risk of damage if ignored
Typical repair cost
DIY fixes can start near $50 (parts only). Shop repairs for P0123 typically run up to $500 depending on the underlying cause and vehicle. Start with the most common cause — Short to 5V reference — before throwing parts at it.
Recommended parts & tools for P0123
Our buyer’s guides cover the tools and parts that pair with AXLY:
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