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Home/DTC Codes/Fiat/Cronos/2018-2025 1.0L I4 Flex Firefly/P0031
P0031

HO2S Heater Control Circuit Low Bank 1 Sensor 1

2018-2025 Fiat Cronos 1.0L I4 Flex Firefly

Low SeverityPowertrainGeneric (SAE)

Description

The voltage in the Bank 1 Sensor 1 O2 heater circuit is lower than expected.

Symptoms

  • Check Engine Light
  • Extended warmup time
  • Poor cold-start emissions

Common Causes

  • Short to ground in heater circuit
  • Faulty O2 sensor
  • Corroded connector

Diagnostic Steps

  1. Test heater circuit voltage
  2. Check for shorts to ground
  3. Test sensor heater resistance
  4. Inspect connector

Repair Notes

Repair short or replace O2 sensor.

Related Codes

P0030HO2S Heater Control Circuit Bank 1 Sensor 1P0032HO2S Heater Control Circuit High Bank 1 Sensor 1

Other Powertrain Codes

P0031 on Other Vehicles

Fiat 124 Spider

2017-2020 1.4L I4 Turbo

Fiat 126p Maluch

1973-2000 0.65L I2 Air-Cooled

Fiat 126p Maluch

1987-2000 0.7L I2 Air-Cooled

Fiat 500

2012-2019 1.4L I4

Fiat 500 Abarth

2012-2019 1.4L I4 Turbo

Fiat 500 BR

2011-2020 1.4L I4 Flex Fire Evo

Fiat 500 PL

2007-2025 1.0L I3 Hybrid FireFly 70

Fiat 500 PL

2007-2025 1.2L I4 Fire 69

Common Questions

What does code P0031 mean on a 2018-2025 Fiat Cronos?

P0031 stands for "HO2S Heater Control Circuit Low Bank 1 Sensor 1". The voltage in the Bank 1 Sensor 1 O2 heater circuit is lower than expected.

What are the symptoms of P0031 on a Fiat Cronos?

Common symptoms of P0031 include: Check Engine Light, Extended warmup time, Poor cold-start emissions.

What causes P0031 on a 2018-2025 Fiat Cronos?

Common causes of P0031 include: Short to ground in heater circuit, Faulty O2 sensor, Corroded connector.

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