Fix P2203: STEP-BY-STEP diagnostic GUIDE!

The P2203: NOx Sensor Circuit High Bank 1 refers to a condition where the voltage in the NOx sensor circuit of bank 1 is higher than expected. This can result from a faulty sensor, wiring issues, or connector problems causing a high-voltage signal.

P2203 – Quick Overview

CodeInformation
MeaningP2203: NOx Sensor Circuit High Bank 1
Is it serious?Yes, it can lead to improper NOx detection, higher emissions, and poor engine performance.
Possible causes– High voltage in NOx sensor circuit in bank 1
– Faulty sensor or wiring issues
– Connector problems
How to diagnose?– Measure voltage in the NOx sensor circuit in bank 1
– Test the NOx sensor for faults
– Inspect wiring and connectors for issues

P2203 Meaning

The P2203: NOx Sensor Circuit High Bank 1 code indicates that the engine control module (ECM) has detected an excessively high voltage in the NOx sensor circuit on bank 1 (the side of the engine containing cylinder 1). The NOx sensor measures nitrogen oxide levels in the exhaust gases to help manage emissions. When the voltage is too high, it can lead to inaccurate NOx readings and ineffective emissions control.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for additional related codes that could provide further insight into the NOx sensor issue.OBD-II Scanner
Measure Voltage in NOx Sensor CircuitUse a multimeter to measure the voltage in the NOx sensor circuit in bank 1. Ensure the voltage is within the manufacturer’s specified range and not too high.Multimeter, Vehicle Manual
Test the NOx SensorUse a diagnostic tool to test the NOx sensor for proper functionality. Compare the sensor’s output to manufacturer specifications to verify it is operating correctly.Multimeter, Diagnostic Tool
Inspect Wiring and ConnectorsVisually inspect the wiring and connectors related to the NOx sensor in bank 1 for damage, corrosion, or loose connections that could cause the high voltage signal.Flashlight, Safety Gloves
Check the NOx Sensor CircuitTest the NOx sensor circuit for proper voltage and continuity to ensure the sensor is communicating properly with the ECM.Multimeter, Wiring Diagram
Repair or Replace Faulty ComponentsIf faulty components are found, such as the NOx sensor or wiring, repair or replace them as necessary to restore proper operation.Replacement Parts, Tools
Clear the Code and Test DriveAfter repairs, clear the P2203 code using an OBD-II scanner and take the vehicle for a test drive to ensure the issue has been resolved.OBD-II Scanner
Recheck for CodesAfter the test drive, re-scan the vehicle to confirm the P2203 code does not return.OBD-II Scanner
Bluetooth OBD-II scanners

OBD-II scanner Buyer’s Guide

  • Scanner features explained
  • Different types of scanners
  • Scanners for coding/odometer/ECU/checks
  • Best picks + discount codes

Download PDF FREE

    Leave a Comment