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P0138

Overview

Code

P0138

Code Type

P

Code Class

P0

System

Engine, Emissions

Severity Level

Low

Emissions Related

true

Drivability Impact

None

Diagnostic Protocol

OBD2

Freeze Frame Useful

true

Code Definition

Diagnostic trouble code P0138 indicates high voltage in the oxygen sensor circuit for Bank 1 Sensor 2

Symptoms

Check Engine Light illuminated

Overview applies to this diagnostic code.

Affected Systems

On This Page

  • Code Definition

  • Symptoms

  • Affected Systems

  • Possible Causes

  • Diagnostic Steps

  • Drive Safety Notes​

More Resources

High downstream O2 voltage may indicate rich conditions or sensor faults

Possible Causes

Faulty oxygen sensor; Wiring short to voltage

Diagnostic Steps

1 Confirm the code; 2 Inspect wiring; 3 Monitor O2 voltage; 4 Replace the sensor if required

Drive Safety Notes

Driving is generally safe, but emissions monitoring may be affected

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