P0043Low SeverityEmissions

HO2S Heater Circuit Low (Bank 1, Sensor 3)

What This Means

The oxygen sensor heater circuit for bank 1, sensor 3 is reading low voltage. A short to ground in the circuit is preventing proper heater operation.

Common Symptoms

Check engine light on
No performance impact
Higher emissions
Emissions test failure

Common Causes

Short to ground
Failed heater
Corroded wiring
Connector damage
Ground circuit fault

Estimated Repair Cost

$100 – $400

Parts and labor (varies by vehicle and location)

Difficulty:Easy

Need This Fixed?

Find certified mechanics near you who can diagnose and repair P0043.

Find a Shop Near You

Search Another Code

For informational purposes only. Diagnostic trouble codes are starting points for diagnosis, not definitive answers. Always consult a certified mechanic for proper diagnosis and repair. Estimated costs vary by vehicle, location, and shop rates.