P0031 on Toyota
HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
P0031 on Toyota vehicles indicates ho2s heater control circuit low (bank 1 sensor 1). Au7o has documented this code across 1 Toyota model — most commonly on Camry. The PCM detects low voltage (short to ground or open) in the heater control circuit of the upstream O2 sensor on Bank 1, Sensor 1. Typical repair costs on Toyota range from $150 to $350, depending on the specific model and root cause.
Common Causes of P0031
- •Open/short in heater wiring
- •Failed O2 sensor heater
- •Corroded connector
- •Blown fuse
P0031 on Toyota by Model
Toyota Camry(1 issue)
- Upstream Air/Fuel Ratio (A/F) Sensor Failure — Heater Circuit Fault and Lean/Rich Codes2007-2017
Toyota's upstream wide-band Air/Fuel Ratio (A/F) sensor (Bank 1, Sensor 1, mounted before the catalytic converter — Toyota's name for the front O2 sensor) is a well-known wear item on the Camry. The internal heater element or sensing cell degrades, setting heater-circuit and lean/rich codes, illuminating the check engine light, and causing rough idle, hesitation, and reduced fuel economy. It is a frequent FAIL item at emissions testing.
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View P0031 across all makes →Frequently Asked Questions
What does P0031 mean on Toyota?▼
P0031 stands for "HO2S Heater Control Circuit Low (Bank 1 Sensor 1)." The PCM detects low voltage (short to ground or open) in the heater control circuit of the upstream O2 sensor on Bank 1, Sensor 1. On Toyota specifically, this code is documented across 1 model.
What causes P0031 on Toyota vehicles?▼
Common causes on Toyota: Open/short in heater wiring, Failed O2 sensor heater, Corroded connector, Blown fuse. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0031 on a Toyota?▼
Repair costs on Toyota range from $150 to $350, depending on the specific model and root cause.
Which Toyota models have P0031 documented?▼
Au7o has documented P0031 on 1 Toyota model: Camry.