AutoCodes – Cadillac – P0137 Cadillac

P0137 Cadillac Code - HO2S Circuit Low Voltage Bank 1 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0137 Cadillac indicates HO2S Circuit Low Voltage Bank 1 Sensor 2.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 14,203

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 26, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0137 Cadillac Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the heated oxygen sensor is shorted to ground if the HO2S voltage is less than 50 mV.

OBDII Code P0137 Cadillac - HO2S Circuit Low Voltage Bank 1 Sensor 2 - AutoCodes.com — P0137 Cadillac Code - HO2S Circuit Low Voltage Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0137 Cadillac?

Faulty Rear Heated Oxygen Sensor Bank 1
Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
Low or high fuel system pressure
Fuel contamination
Faulty fuel injectors
Exhaust gas leaks
Engine vacuum leaks

How to Fix the DTC P0137 Cadillac?

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 does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor (HO2S) Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0137 Cadillac 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.

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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.

Frequently Asked Questions about P0137 Cadillac Code

1. What are the common symptoms of OBDII code P0137 (HO2S Circuit Low Voltage Bank 1 Sensor 2) in a Cadillac?

- Common symptoms include poor fuel economy, rough idling, engine misfires, and the illumination of the check engine light.

2. What causes the OBDII code P0137 to trigger in a Cadillac?

- The code P0137 is typically triggered when there is a problem with the oxygen sensor (Bank 1 Sensor 2) sending a signal indicating low voltage to the engine control module.

3. How can I diagnose the issue causing code P0137 in my Cadillac?

- Diagnosis involves using an OBDII scanner to read the code and checking the wiring and connectors related to the Bank 1 Sensor 2 oxygen sensor for any damage or corrosion.

4. Can a faulty catalytic converter cause code P0137 in a Cadillac?

- Yes, a faulty catalytic converter can cause the OBDII code P0137 to trigger as it may affect the oxygen sensor's readings and lead to low voltage signals.

5. What are the potential repair options for resolving code P0137 in a Cadillac?

- Possible repair options include replacing the Bank 1 Sensor 2 oxygen sensor, repairing any damaged wiring or connectors, and addressing any issues with the catalytic converter if necessary.

6. Is it safe to continue driving my Cadillac with the P0137 code present?

- While it may be safe to drive the vehicle in the short term, it is recommended to address the issue causing the code P0137 as soon as possible to prevent potential damage to the engine or catalytic converter.

7. Will resetting the check engine light make the P0137 code go away permanently?

- Resetting the check engine light without addressing the underlying issue causing the P0137 code will not make it go away permanently. The code is likely to reappear once the problem persists.

8. How long does it typically take to repair the P0137 code in a Cadillac?

- The repair time for the P0137 code can vary depending on the exact cause of the issue. In general, it may take anywhere from 30 minutes to a few hours to diagnose and repair the problem.

9. Can I fix the P0137 code in my Cadillac myself, or should I take it to a professional mechanic?

- If you have experience working on automotive electrical systems and have the necessary tools, you may be able to address the P0137 code yourself. However, if you are unsure or unfamiliar with diagnostic procedures, it is recommended to seek help from a professional mechanic.

10. Are there any maintenance tips to prevent the recurrence of the P0137 code in a Cadillac?

- To help prevent the P0137 code from reoccurring, it is important to follow regular maintenance schedules, such as replacing oxygen sensors at recommended intervals, ensuring proper fuel quality, and addressing any engine performance issues promptly.