The P2243: O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 1 refers to an open circuit condition detected in the reference voltage circuit of the oxygen (O2) sensor for Bank 1 Sensor 1. This means there is a lack of continuity in the circuit, which may prevent the sensor from functioning properly. The potential causes include wiring issues, a faulty O2 sensor, or connector problems, and these must be addressed to ensure the sensor can provide accurate readings for air-fuel mixture adjustments.
P2243 – Quick Overview
Code | Information |
---|---|
Meaning | P2243: O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 1 |
Is it serious? | Yes, as an open circuit in the reference voltage can lead to incorrect air-fuel mixture control, potentially reducing fuel efficiency and increasing emissions. |
Possible causes | – Open circuit in O2 sensor reference voltage for Bank 1 Sensor 1 – Faulty O2 sensor – Wiring issues – Connector problems |
How to diagnose? | – Inspect the O2 sensor reference voltage circuit for continuity – Test the O2 sensor for proper operation – Check wiring and connectors for faults |
P2243 Meaning
The P2243: O2 Sensor Reference Voltage Circuit/Open Bank 1 Sensor 1 code indicates that the reference voltage circuit for the O2 sensor on Bank 1 Sensor 1 has an open circuit or disconnection. This means that the oxygen sensor is unable to receive the reference voltage required for proper operation, leading to incorrect readings. These readings are critical for the engine control unit to maintain the correct air-fuel ratio, and an open circuit can result in poor performance, inefficient fuel usage, and increased emissions.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to determine if there are additional codes related to the O2 sensor or other engine control components. This can help identify if there are multiple faults or an isolated issue. | OBD-II Scanner |
Inspect the O2 Sensor Reference Voltage Circuit for Continuity | Use a multimeter to check for continuity in the O2 sensor reference voltage circuit. Lack of continuity indicates an open circuit that needs to be repaired. Trace the wiring to locate the break and repair it as necessary. | Multimeter, Vehicle Service Manual |
Test the O2 Sensor | Use a diagnostic tool to test the O2 sensor itself to verify its operation. If the sensor is defective, it will need to be replaced. The test should include checking the sensor’s response to determine if it can operate properly when given the correct reference voltage. | Multimeter, Diagnostic Tool |
Check Wiring and Connectors for Faults | Inspect all wiring and connectors related to Bank 1 Sensor 1. Look for any visible damage such as broken or frayed wires, corrosion on terminals, or loose connectors that could lead to an open circuit. Repair or replace any damaged wiring or connectors. | Flashlight, Safety Gloves |
Inspect the Sensor Connector Condition | Examine the connector for bent pins, corrosion, or poor fit, which could interrupt the flow of the reference voltage. Make sure the connector is clean and securely attached. | Flashlight |
Clear the Code and Test Drive | After making any necessary repairs, use an OBD-II scanner to clear the fault code. Conduct a test drive while monitoring the O2 sensor to confirm the issue is resolved and that the circuit is functioning correctly. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | Re-scan the vehicle after the test drive to ensure that the P2243 code has not returned. If the code reappears, further investigation may be required to find the root cause of the issue. | OBD-II Scanner |

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