O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1
2018-2025 Fiat Cronos 1.0L I4 Flex Firefly
Description
The upstream O2 sensor on Bank 1 shows no switching activity - the signal is flat.
Symptoms
- Check Engine Light
- Poor fuel economy
- Rich or lean running
- Failed emissions
Common Causes
- Faulty O2 sensor
- Open heater circuit
- Wiring issue
- Exhaust leak
- Fuel system problem preventing closed loop
Diagnostic Steps
- Check O2 sensor voltage (should not be stuck)
- Test heater circuit
- Inspect wiring
- Check for exhaust leaks
Repair Notes
Replace O2 sensor. Check heater circuit and wiring first.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0134 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 P0134 mean on a 2018-2025 Fiat Cronos?
P0134 stands for "O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1". The upstream O2 sensor on Bank 1 shows no switching activity - the signal is flat.
What are the symptoms of P0134 on a Fiat Cronos?
Common symptoms of P0134 include: Check Engine Light, Poor fuel economy, Rich or lean running, Failed emissions.
What causes P0134 on a 2018-2025 Fiat Cronos?
Common causes of P0134 include: Faulty O2 sensor, Open heater circuit, Wiring issue, Exhaust leak, Fuel system problem preventing closed loop.