O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 2
P2235 indicates that the oxygen sensor signal circuit on Bank 2 Sensor 2 is shorted to the heater circuit, causing abnormal voltage readings. This electrical fault prevents the PCM from accurately reading exhaust oxygen levels, leading to improper fuel mixture correction and increased emissions.
What You Might Notice
- Service Engine Soon light illuminated
- Reduced fuel economy
- Diminished engine performance or hesitation
- Stored misfire codes or lean/rich condition codes
- Rough idle or stumbling during acceleration
Most Common Causes
- 1
Defective oxygen sensor
The O2 sensor itself has failed internally with a short between the signal wire and heater circuit, preventing proper voltage output to the PCM.
- 2
Damaged sensor wiring harness
The wiring connecting the oxygen sensor has chafed, corroded, or been pinched, causing the signal and heater wires to short together.
- 3
Faulty oxygen sensor connector
The connector pins are corroded, loose, or damaged, creating an intermittent short between the heater and signal circuits.
- 4
PCM input circuit failure
The powertrain control module's oxygen sensor input circuit has developed a fault, though this is less common than sensor or wiring issues.
How to Diagnose It
- 1
Check Defective oxygen sensor — The O2 sensor itself has failed internally with a short between the signal wire and heater circuit, preventing proper voltage output to the PCM.
- 2
Check Damaged sensor wiring harness — The wiring connecting the oxygen sensor has chafed, corroded, or been pinched, causing the signal and heater wires to short together.
- 3
Check Faulty oxygen sensor connector — The connector pins are corroded, loose, or damaged, creating an intermittent short between the heater and signal circuits.
- 4
Check PCM input circuit failure — The powertrain control module's oxygen sensor input circuit has developed a fault, though this is less common than sensor or wiring issues.
How to Fix It
- 1
Replace oxygen sensor Bank 2 Sensor 2
Locate the downstream oxygen sensor on Bank 2 (passenger side on V-configured engines) and replace it with a new or remanufactured unit. Ensure proper torque specifications are followed and the connector is fully seated.
- 2
Inspect and repair sensor wiring
Check the oxygen sensor harness from the sensor to the PCM for chafing, corrosion, or pinches. Repair or replace damaged wiring and ensure proper routing away from heat sources.
- 3
Clean or replace sensor connector
Disconnect and inspect the oxygen sensor connector for corrosion or damage. Clean contacts with electrical contact cleaner or replace the connector assembly if pins are damaged.
- 4
Clear code and test drive
After repairs, use a diagnostic scanner to clear the P2235 code and perform a test drive to verify the fix. Monitor for code return over several drive cycles.
Need a deeper diagnosis?
Search for related repair guides or browse by system.