AutoCodes – Chevrolet – P1138 Chevrolet

P1138 Chevrolet Code - HO2S Circuit High Voltage Sensor 2

Quick Answer

In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide. Common causes include Faulty HO2S Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1138 Chevrolet indicates HO2S Circuit High Voltage Sensor 2.
Common causes: Common causes include Faulty HO2S Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 16,907

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 12, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1138 Chevrolet Description

In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide. The Powertrain Control Module (PCM) can monitor this process by using a rear Heated Oxygen Sensor 2 (HO2S 2). The HO2S 2, located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This signal indicates the catalyst's ability to effectively convert the exhaust emissions. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front Heated Oxygen Sensor 1 (HO2S 1).

OBDII Code P1138 Chevrolet - HO2S Circuit High Voltage Sensor 2 - AutoCodes.com — P1138 Chevrolet Code - HO2S Circuit High Voltage Sensor 2

What does this mean?

What are the Possible Causes of the DTC P1138 Chevrolet?

Faulty HO2S Bank 1 Sensor 2
HO2S Bank 1 Sensor 2 harness is open or shorted
HO2S Bank 1 Sensor 2 circuit poor electrical connection

How to Fix the DTC P1138 Chevrolet?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1138 Chevrolet code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1138 Chevrolet code?

Need more information on how to fix the P1138 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1138 Chevrolet code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.