Quick Answer
B0747 means: DTC B0747 signals a malfunction in the Transmission Control Module (TCM), affecting the vehicle's transmission performance.
Can I drive with B0747? Immediate attention is recommended to avoid further transmission damage.
Common Questions
What does B0747 mean and how does it affect my car?
DTC B0747 indicates a malfunction in the Transmission Control Module (TCM), which plays a vital role in controlling your vehicle's transmission. If your car shows this code, it might experience issues like rough shifting or slipping gears. Ignoring it can lead to severe transmission problems, so it's essential to have it checked out.
What are the most common causes of B0747 and how much does it cost to fix?
Common causes of B0747 include a faulty TCM, damaged wiring, or software glitches. Repair costs can range from $50 for a software update to over $1,200 for a complete TCM replacement. It's always best to consult with a professional for an accurate diagnosis.
Can I drive my car with B0747 or should I stop immediately?
While you might be able to drive your car temporarily, it’s not advisable. The underlying issue can worsen, potentially leading to complete transmission failure. It’s best to have your vehicle inspected as soon as possible.
How can I diagnose B0747 myself using GeekOBD APP?
Using the GeekOBD APP, connect to your vehicle’s OBD2 port and retrieve any stored DTCs. The app will provide information on the B0747 code and any related issues, helping you understand what might be wrong with your transmission.
What vehicles are most commonly affected by B0747?
DTC B0747 is frequently seen in models such as the 2015-2018 Honda Civic, 2016-2019 Toyota RAV4, and various other Honda and Toyota vehicles. If your vehicle falls within these models and years, keep an eye out for symptoms of transmission issues.
How can I prevent B0747 from happening again?
To prevent DTC B0747, ensure regular maintenance of your vehicle’s transmission, including fluid changes and inspections of wiring and connectors. Keeping your software updated can also help mitigate issues with the TCM.
What is B0747?
The Diagnostic Trouble Code (DTC) B0747 indicates a problem with the Transmission Control Module (TCM), which is a critical component that manages the transmission's operations. This code is particularly common in vehicles like the 2015-2018 Honda Civic and 2016-2019 Toyota RAV4. When the TCM fails or detects an anomaly, it triggers this code to alert the driver that there may be an issue affecting the vehicle's performance. The TCM is responsible for regulating the shifting of gears and ensuring that the engine operates efficiently. If this module malfunctions, you might experience erratic shifting, a slipping transmission, or even complete transmission failure in severe cases. Ignoring this code can lead to more significant transmission issues and costly repairs. Therefore, it’s crucial to address DTC B0747 promptly to maintain vehicle safety and reliability.
System: B - Body (Airbags, Lighting, Security, Climate Control)
Symptoms
Common symptoms when B0747 is present:
- The check engine light illuminates, remaining active until the issue is resolved.
- Transmission experiences rough shifting or delay in gear changes, making driving uncomfortable.
- Vehicle may enter limp mode, reducing power and limiting speed to prevent further damage.
- Unusual sounds such as grinding or whining when changing gears, indicating a mechanical issue.
- Fuel efficiency may noticeably decrease, with a drop of 10-20% as the transmission struggles to function properly.
Possible Causes
Most common causes of B0747 (ordered by frequency):
- The most common cause of DTC B0747 is a faulty TCM, accounting for about 50% of cases. This can occur due to age, exposure to heat, or electrical shorts.
- Another possible cause is damaged wiring or poor connections to the TCM, which can prevent it from receiving or sending signals effectively.
- A third cause could be software issues within the TCM. Updating the software can sometimes resolve these glitches.
- Less commonly, a malfunctioning transmission solenoid can trigger this code, leading to erratic shifting behavior.
- A rare cause may involve internal transmission damage, which could result from neglecting regular maintenance or low transmission fluid levels.
B0747 Repair Costs
Cost Breakdown by Repair Type
TCM Replacement
Replacing the faulty Transmission Control Module with a new unit.
- Total: $500 - $1,200
- Success rate: 90%
Wiring Repair
Repairing damaged wiring or connectors related to the TCM.
- Total: $100 - $300
- Success rate: 80%
Software Update
Updating the TCM software to the latest version.
- Total: $50 - $150
- Success rate: 70%
Money-Saving Tips for B0747
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional B0747 Diagnosis Process
Follow these systematic steps to accurately diagnose B0747. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Conduct a visual inspection of the wiring and connectors to the TCM, looking for signs of damage or corrosion (5-10 minutes)
Step 1: Conduct a visual inspection of the wiring and connectors to the TCM, looking for signs of damage or corrosion (5-10 minutes).
Step 2: Step 2: Use an OBD2 scanner, such as the GeekOBD APP, to retrieve the DTCs and assess any additional codes or freeze frame data (10-15 minutes)
Step 2: Use an OBD2 scanner, such as the GeekOBD APP, to retrieve the DTCs and assess any additional codes or freeze frame data (10-15 minutes).
Step 3: Step 3: Test the TCM and associated components with a multimeter to check for proper voltage and resistance (20-30 minutes)
Step 3: Test the TCM and associated components with a multimeter to check for proper voltage and resistance (20-30 minutes).
Step 4: Step 4: If repairs or replacements are made, conduct a system function test to ensure everything operates correctly and clear the codes (10-15 minutes)
Step 4: If repairs or replacements are made, conduct a system function test to ensure everything operates correctly and clear the codes (10-15 minutes).
Step 5: Step 5: Perform a road test under various conditions to confirm that the repair has resolved the issue (15-20 minutes)
Step 5: Perform a road test under various conditions to confirm that the repair has resolved the issue (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: Honda Civic TCM Replacement
Vehicle: 2017 Honda Civic, 45,000 miles
Problem: Customer reported rough shifting and check engine light on.
Diagnosis: OBD2 scan revealed code B0747. Visual inspection showed corroded wiring to the TCM.
Solution: Replaced the TCM and repaired the wiring harness.
Cost: $900 (parts: $700, labor: $200)
Result: After repairs, the vehicle shifted smoothly, and the check engine light was cleared.
Case Study 2: Toyota RAV4 Wiring Repair
Vehicle: 2018 Toyota RAV4, 30,000 miles
Problem: Customer experienced delayed shifting and check engine light.
Diagnosis: DTC B0747 confirmed. Wiring harness showed signs of wear.
Solution: Repaired the damaged wiring and cleared the code.
Cost: $200 (parts: $50, labor: $150)
Result: Customer reported normal shifting behavior after the repair.