p2237
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Toyota · SUVs
O2 Sensor Positive Current Control Circuit Low Bank 1 Sensor 1
Quick Answer
Error code P2237 on your Toyota SUVs means: O2 Sensor Positive Current Control Circuit Low Bank 1 Sensor 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Failed air/fuel ratio sensor internal pump cell
  2. Open circuit in the sensor positive current control wiring
  3. Corroded connector at the A/F sensor
  4. Faulty ECM A/F sensor control circuit
  5. Water intrusion into the sensor connector causing a short
How to Fix It
1
Inspect the Bank 1 Sensor 1 A/F sensor connector for corrosion or water damage
2
Measure the sensor circuit voltages at the ECM connector and compare to wiring diagram specifications
3
Test the A/F sensor wiring harness for continuity between the sensor and ECM
4
Use a scan tool to monitor A/F sensor current output and compare to expected values
5
Replace the air/fuel ratio sensor if the internal pump cell has failed
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
Parts You May Need
Air/fuel ratio sensor (Bank 1 Sensor 1)
Wiring harness repair kit
Dielectric grease
Connector sealing boot
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