P2245 — O2 Sensor Reference Voltage Circuit Low Bank 1 Sensor 1

P2245 — O2 Sensor Reference Voltage Circuit Low Bank 1 Sensor 1. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: damaged sensor wiring or connector, exhaust leak near the sensor, oil or coolant contamination of the sensor tip.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK You can usually drive for a while: the engine runs on a default fuel strategy, which costs you fuel and emissions. Fix it soon — prolonged driving with a bad O2 sensor can overheat and damage the catalytic converter.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2245 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the oxygen sensor circuit for damage, corrosion, chafing or poor contact.
  4. Subsystem check Watch the sensor voltage in live data: a healthy upstream sensor switches rapidly between roughly 0.1 and 0.9 V.
  5. Subsystem check Measure heater resistance on the sensor connector and check the heater fuse and relay.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2245 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2245 (parts and labor, USD, independent shop rates): Replace the oxygen sensor: $150–$450; Fix an exhaust leak near the sensor: $100–$300; Repair sensor wiring: $80–$250. Overall, fixing P2245 usually costs between $80 and $450. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Is it safe to drive with P2245?

You can usually drive for a while: the engine runs on a default fuel strategy, which costs you fuel and emissions. Fix it soon — prolonged driving with a bad O2 sensor can overheat and damage the catalytic converter.

How much does it cost to fix P2245?

Replace the oxygen sensor — $150–$450; Fix an exhaust leak near the sensor — $100–$300; Repair sensor wiring — $80–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

What does OBD2 code P2245 mean?

P2245 — O2 Sensor Reference Voltage Circuit Low Bank 1 Sensor 1. A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: damaged sensor wiring or connector, exhaust leak near the sensor, oil or coolant contamination of the sensor tip.

How do I diagnose P2245 myself?

Start with a scan: confirm P2245, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the oxygen sensor circuit, and verify the suspect component against live data before buying parts.

What is the most common cause of P2245?

The most common causes are: damaged sensor wiring or connector, exhaust leak near the sensor, oil or coolant contamination of the sensor tip.

What does P2245 mean?

When P2245 appears on a scan, it means the control module has flagged a problem in the oxygen sensor circuit: O2 sensor reference voltage circuit low bank 1 sensor 1. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

In this definition, “Bank 1” is the side of the engine that contains cylinder 1 and “Sensor 1” is the upstream (before the catalytic converter) sensor. Mixing up banks and sensor positions is the most common DIY mistake with this code — verify the physical location before replacing anything.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores P2245 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

What causes P2245?

  • ECM signal circuit fault
  • aged or contaminated oxygen sensor
  • oil or coolant contamination of the sensor tip
  • damaged sensor wiring or connector

Common symptoms of P2245

  • Check Engine Light on
  • increased fuel consumption
  • sluggish throttle response
  • rough idle
  • failed emissions test

How to diagnose P2245

  1. Connect an OBD2 scanner, confirm P2245 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the oxygen sensor circuit for damage, corrosion, chafing or poor contact.
  4. Watch the sensor voltage in live data: a healthy upstream sensor switches rapidly between roughly 0.1 and 0.9 V.
  5. Measure heater resistance on the sensor connector and check the heater fuse and relay.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2245 does not return.

How to fix P2245

Start with the cheapest and most common causes before replacing expensive parts:

  • Replace the oxygen sensor — $150–$450
  • Fix an exhaust leak near the sensor — $100–$300
  • Repair sensor wiring — $80–$250

How much does it cost to fix P2245?

Repair cost depends on which component actually failed. Typical scenarios for P2245 (parts and labor, USD, independent shop rates):

  • Replace the oxygen sensor: $150–$450
  • Fix an exhaust leak near the sensor: $100–$300
  • Repair sensor wiring: $80–$250

Overall, fixing P2245 usually costs between $80 and $450. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2245?

You can usually drive for a while: the engine runs on a default fuel strategy, which costs you fuel and emissions. Fix it soon — prolonged driving with a bad O2 sensor can overheat and damage the catalytic converter.

Related OBD2 codes