AutoCodes – Generic – C0307

C0307 Code - Motor A/B Circuit Range/Performance

Quick Answer

The transfer case motor is a bi-directional, permanent magnet, D.C. Common causes include Faulty Transfer Case Motor, Transfer Case Motor harness is open or shorted, Transfer Case Motor 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: C0307 indicates Motor A/B Circuit Range/Performance.
Common causes: Common causes include Faulty Transfer Case Motor, Transfer Case Motor harness is open or shorted, Transfer Case Motor 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 6,532

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 Jun 18, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0307 Description

The transfer case motor is a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing Motor Control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, AUTO 4WD, 2H, N, and 4L ranges. While the transfer case motor is energized the transfer case shift control module also energizes the solenoid for the transfer case lock. The motor lock is disabled (locking action released) and free turning of the transfer case motor and sector shaft is then allowed.
This DTC detects a short to ground in Motor Control A or Motor Control B CKT.

OBDII Code C0307 - Motor A/B Circuit Range/Performance - AutoCodes.com — C0307 Code - Motor A/B Circuit Range/Performance

What does this mean?

What are the Possible Causes of the DTC C0307?

Faulty Transfer Case Motor
Transfer Case Motor harness is open or shorted
Transfer Case Motor circuit poor electrical connection

How to Fix the DTC C0307?

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 C0307 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 C0307 code?

Need more information on how to fix the C0307 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0307 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0307 Buick — Motor A/B Circuit Range/Performance
C0307 Cadillac — Motor A/B Circuit Range/Performance
C0307 Chevrolet — Motor A/B Circuit Range/Performance
C0307 GMC — Motor A/B Circuit Range/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 C0307 Code

1. What are the common symptoms of OBDII code C0307 (Motor A/B Circuit Range/Performance)?

- Common symptoms include rough idling, stalling, reduced engine performance, and illuminated Check Engine Light.

2. What are the possible causes of OBDII code C0307?

- Possible causes include a faulty motor A/B circuit, damaged wiring or connectors, low transmission fluid level, or a malfunctioning transmission control module.

3. How can I diagnose the OBDII code C0307?

- Diagnosis typically involves using a scan tool to retrieve the fault code, inspecting the motor A/B circuit components, checking for loose connections, and testing the transmission functions.

4. Can a DIYer repair OBDII code C0307 at home?

- Depending on your skill level and access to tools, you may be able to repair this code at home by fixing wiring issues, replacing faulty components, or addressing low transmission fluid levels.

5. What are some repair tips for resolving OBDII code C0307?

- Repair tips include checking and repairing any damaged wiring, ensuring proper fluid levels, clearing the code after repairs, and conducting a test drive to confirm the issue is resolved.

6. Is it safe to continue driving with OBDII code C0307 present?

- It is not recommended to continue driving with this code present, as it can lead to further damage to the transmission system and may result in unsafe driving conditions.

7. How much does it typically cost to repair OBDII code C0307 at a mechanic's shop?

- Repair costs can vary depending on the specific issue causing the code, but expect to pay anywhere from $100 to $500 for parts and labor at a mechanic's shop.

8. Can resetting the Check Engine Light clear OBDII code C0307 permanently?

- Resetting the Check Engine Light may temporarily clear the code, but if the underlying issue causing the code is not addressed, the code is likely to return.

9. Are there any recalls related to OBDII code C0307?

- Check with the manufacturer or visit the National Highway Traffic Safety Administration (NHTSA) website to see if there are any recalls related to this specific OBDII code.

10. How often should I perform maintenance checks to prevent OBDII code C0307 from occurring?

- Regular maintenance checks, including inspecting wiring, fluid levels, and transmission components, can help prevent OBDII code C0307 from occurring. Consider performing these checks during routine service intervals or if you notice any symptoms of transmission issues.