Quick Answer
B0746 means: B0746 indicates a fault in the transmission fluid temperature sensor circuit.
Can I drive with B0746? Immediate attention is recommended to prevent transmission damage.
Common Questions
What does B0746 mean and how does it affect my car?
B0746 signifies a malfunction in the transmission fluid temperature sensor circuit. It can lead to poor transmission performance, overheating, and ultimately, damage if not addressed. This can affect your vehicle's shifting, fuel efficiency, and overall drivability.
What are the most common causes of B0746 and how much does it cost to fix?
The most frequent causes include a faulty transmission fluid temperature sensor and wiring issues. Repair costs can range from $100 to $300 depending on the specific issue and required parts.
Can I drive my car with B0746 or should I stop immediately?
It's best to avoid driving your vehicle if you have a B0746 code, as it can lead to further transmission damage. If you must drive, do so cautiously and seek repairs as soon as possible.
How can I diagnose B0746 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for diagnostic trouble codes, view real-time data from the transmission fluid temperature sensor, and check for any irregularities in readings that might indicate the issue.
What vehicles are most commonly affected by B0746?
The B0746 code is commonly found in models like the 2015-2018 Honda Accord, 2012-2017 Toyota Camry, and other vehicles with similar transmission systems. Always check for any recalls or technical service bulletins.
How can I prevent B0746 from happening again?
To prevent B0746, regularly check and maintain your transmission fluid levels, avoid overheating your vehicle, and have periodic inspections of electrical connections related to the transmission.
What is B0746?
DTC B0746 indicates a problem with the transmission fluid temperature sensor circuit, which can be found in various vehicles including the Honda Accord and Toyota Camry. This diagnostic trouble code is triggered when the Engine Control Module (ECM) detects a voltage reading from the transmission fluid temperature sensor that is outside the expected range. The transmission fluid temperature sensor plays a crucial role in monitoring the temperature of the fluid, which is vital for maintaining optimal transmission performance and preventing overheating. If the fluid temperature is too high, it can lead to poor shifting, reduced fuel efficiency, and potential damage to the transmission. In practical terms, this means that if you see the B0746 code, you might experience issues like the check engine light illuminating, erratic shifting, or even slipping gears. Ignoring this code could result in serious transmission damage, leading to costly repairs down the line. Therefore, addressing this issue promptly is essential to ensure the longevity and reliability of your vehicle's transmission system.
System: B - Body (Airbags, Lighting, Security, Climate Control)
Symptoms
Common symptoms when B0746 is present:
- Check engine light stays on constantly, indicating an underlying issue that needs attention.
- Erratic shifting behavior, where the transmission hesitates or shifts unpredictably during driving.
- Transmission overheating warning may activate, especially during strenuous driving conditions.
- Decreased fuel economy, often noticeable as a 10-15% drop in efficiency due to improper transmission function.
- Increased engine RPMs without a corresponding increase in vehicle speed, suggesting potential slipping.
Possible Causes
Most common causes of B0746 (ordered by frequency):
- The most common cause of B0746 is a faulty transmission fluid temperature sensor, with a likelihood of around 60%. This sensor may fail due to wear or electrical issues.
- Another common cause is wiring issues, such as damaged or corroded connectors, which may account for about 25% of cases. Corrosion can lead to unreliable signals being sent to the ECM.
- A third cause could be low transmission fluid levels, which can result from leaks. Regularly checking fluid levels can prevent this issue.
- Less common but serious causes include internal transmission damage or failure, which may require extensive repairs or replacement.
- A rare cause might be a malfunctioning ECM, which can lead to incorrect readings from various sensors.
B0746 Repair Costs
Cost Breakdown by Repair Type
Transmission Fluid Temperature Sensor Replacement
Replacing the faulty transmission fluid temperature sensor to restore proper function.
- Total: $150 - $300
- Success rate: 90%
Wiring Repair
Repairing or replacing damaged wiring or connectors associated with the sensor circuit.
- Total: $100 - $250
- Success rate: 85%
Transmission Fluid Change
Changing the transmission fluid to ensure proper levels and quality.
- Total: $80 - $150
- Success rate: 80%
Money-Saving Tips for B0746
- 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 B0746 Diagnosis Process
Follow these systematic steps to accurately diagnose B0746. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid temperature sensor and wiring (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the transmission fluid temperature sensor and wiring (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor for any reoccurrence of the code (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and monitor for any reoccurrence of the code (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: Transmission Fluid Temperature Sensor Replacement in a 2016 Honda Accord
Vehicle: 2016 Honda Accord, 75,000 miles
Problem: Customer reported check engine light and erratic shifting.
Diagnosis: Diagnostic scan revealed B0746 code. Visual inspection found damaged sensor wiring.
Solution: Replaced the transmission fluid temperature sensor and repaired wiring.
Cost: $250 (sensor: $150, labor: $100)
Result: Resolved check engine light and restored proper shifting performance.
Case Study 2: Wiring Issues in a 2014 Toyota Camry
Vehicle: 2014 Toyota Camry, 90,000 miles
Problem: Customer experienced overheating transmission and warning lights.
Diagnosis: B0746 code indicated a fault in the temperature sensor circuit. Inspection revealed corroded connectors.
Solution: Repaired wiring and replaced corroded connectors.
Cost: $200 (labor: $100, parts: $100)
Result: Transmission function restored and overheating issues resolved.