What Does P2240 Mean?
The PCM has detected an open circuit or malfunction in the positive current control circuit for the oxygen sensor located in Bank 2, Sensor 1 (pre-catalytic converter). This affects the sensor's ability to heat up properly and provide accurate readings.
Common Causes
35%
Damaged or corroded wiring/connectors in the O2 sensor heater circuit
30%
Failed oxygen sensor with internal heater circuit failure
20%
Blown fuse or faulty relay for O2 sensor heater circuit
10%
PCM internal driver circuit failure
5%
Open circuit in ground path for O2 sensor heater
Diagnostic Steps
1
Step 1: Inspect O2 sensor connector and wiring for damage, corrosion, or loose connections on Bank 2 Sensor 1
2
Step 2: Check O2 sensor heater fuse and relay; replace if blown or faulty
3
Step 3: Measure resistance across O2 sensor heater element (typically 3-10 ohms when cold)
4
Step 4: Test for battery voltage at O2 sensor heater power supply wire with ignition on
5
Step 5: If all circuits test normal, replace O2 sensor; if problem persists, test PCM driver circuit
Estimated Repair Cost
$150 - $400
Parts + labor, varies by vehicle and location
The PCM has detected an open circuit or malfunction in the positive current control circuit for the oxygen sensor located in Bank 2, Sensor 1 (pre-catalytic converter). This affects the sensor's ability to heat up properly and provide accurate readings.
The most common cause of P2240 (O2 Sensor Positive Current Control Circuit/Open Bank 2 Sensor 1) is: Damaged or corroded wiring/connectors in the O2 sensor heater circuit
Typical repair costs for P2240 range from $150 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive short distances but may experience reduced fuel economy and increased emissions. Extended operation may damage catalytic converter.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2240 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Emissions Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
