AutoCodes – Generic – B3970

B3970 Code - Output Driver Module Performance

Quick Answer

The Body Control Module (BCM) internally grounds the driver door unlock relay control circuit for the driver door unlock relay when it receives an unlock switch signal from either door lock switch. Common causes include Faulty Driver Door Unlock Relay, Driver Door Unlock Relay harness is open or shorted, Driver Door Unlock Relay 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: B3970 indicates Output Driver Module Performance.
Common causes: Common causes include Faulty Driver Door Unlock Relay, Driver Door Unlock Relay harness is open or shorted, Driver Door Unlock Relay 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.

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Code Popularity 561

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 25, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3970 Description

The Body Control Module (BCM) internally grounds the driver door unlock relay control circuit for the driver door unlock relay when it receives an unlock switch signal from either door lock switch. When the BCM grounds the driver door unlock relay control circuit the driver door unlock relay is energized and unlocks the driver door. The Diagnostic Trouble Code (DTC) will set if the driver door unlock relay control circuit is shorted to ground or open for more then one second.

OBDII Code B3970 - Output Driver Module Performance - AutoCodes.com — B3970 Code - Output Driver Module Performance

What does this mean?

What are the Possible Causes of the DTC B3970?

Faulty Driver Door Unlock Relay
Driver Door Unlock Relay harness is open or shorted
Driver Door Unlock Relay circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B3970?

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 B3970 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 B3970 code?

Need more information on how to fix the B3970 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3970 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3970 Buick — Output Driver Module Performance
B3970 Cadillac — Output Driver Module Performance
B3970 Chevrolet — Output Driver Module Performance
B3970 GMC — Output Driver Module Performance

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 B3970 Code

1. What are the common symptoms of OBDII code B3970 (Output Driver Module Performance)?

- Common symptoms include engine misfires, rough idling, poor acceleration, and issues with the transmission.

2. What causes the OBDII code B3970 to trigger?

- This code is typically triggered by a malfunction in the output driver module, which controls various components in the vehicle such as the ignition coils and fuel injectors.

3. How can I diagnose the OBDII code B3970?

- Diagnosing this code usually involves using a diagnostic scanner to retrieve the code, checking the wiring and connections to the output driver module, and testing the module itself for proper function.

4. What are the potential consequences of ignoring the OBDII code B3970?

- Ignoring this code can lead to poor engine performance, decreased fuel efficiency, and potential damage to other engine components over time.

5. Can a DIY enthusiast repair the OBDII code B3970 at home?

- Repairing this code may require advanced automotive knowledge and specialized tools, so it is recommended to consult a professional mechanic for proper diagnosis and repair.

6. Is it safe to drive with the OBDII code B3970 active?

- It is not recommended to drive with this code active, as it can lead to further damage to the vehicle and potential safety hazards on the road.

7. How much does it typically cost to repair the OBDII code B3970?

- The cost of repair can vary depending on the extent of the issue, but it may involve replacing the output driver module, which can range from $200 to $500 including parts and labor.

8. Are there any preventive measures to avoid triggering the OBDII code B3970?

- Regular maintenance of the vehicle, such as checking and replacing ignition components as needed, can help prevent issues that may trigger this code.

9. Can a faulty output driver module cause other OBDII codes to trigger?

- Yes, a malfunctioning output driver module can cause a range of other OBDII codes to trigger, affecting various engine and transmission functions.

10. How long does it typically take to repair the OBDII code B3970?

- The repair time can vary depending on the availability of parts and the complexity of the issue, but it may take a few hours to a full day for a professional mechanic to diagnose and repair the problem.