Quick Answer
B0704 means: B0704 indicates a high input signal from the Transmission Range Sensor, affecting transmission performance.
Can I drive with B0704? Immediate attention is recommended to prevent potential damage to the transmission system.
Common Questions
What does B0704 mean and how does it affect my car?
The B0704 code signifies a problem with the Transmission Range Sensor, which can lead to erratic shifts and poor performance. It’s crucial for ensuring smooth gear changes in your vehicle.
What are the most common causes of B0704 and how much does it cost to fix?
Common causes include a faulty Transmission Range Sensor, wiring issues, and low transmission fluid levels. Repair costs can range from $150 to $300 for sensor replacement.
Can I drive my car with B0704 or should I stop immediately?
It's advised to stop driving if you see the B0704 code. Continuing to drive could lead to severe transmission damage and higher repair costs.
How can I diagnose B0704 myself using GeekOBD APP?
Using the GeekOBD APP, scan for codes and analyze freeze frame data, which provides context for the failure. This helps pinpoint whether the issue lies with the sensor or wiring.
What vehicles are most commonly affected by B0704?
The B0704 code is frequently seen in 2015-2018 Honda Accord and Toyota Camry models, among others. Always check for any recalls or technical service bulletins related to this code.
How can I prevent B0704 from happening again?
Regular maintenance, such as checking transmission fluid levels and conducting routine inspections, can help prevent the occurrence of code B0704.
What is B0704?
The diagnostic trouble code (DTC) B0704 indicates that the Transmission Range Sensor, also known as the Transmission Position Sensor, has detected a high input signal. This sensor is crucial as it informs the engine control module (ECM) about the position of the transmission gear. A high input signal often suggests that the sensor is malfunctioning, or there could be an issue with the wiring or connectors leading to the sensor. When the sensor fails, it can cause transmission-related problems, leading to erratic shifting or even making the vehicle undriveable. In practical terms, if you see this code, your vehicle's transmission may not shift correctly, resulting in poor performance and safety concerns. Ignoring this code could lead to further damage to the transmission system, which can be costly to repair later on. For car owners, understanding this code is essential, as it could mean the difference between a simple fix and a significant repair bill.
System: B - Body (Airbags, Lighting, Security, Climate Control)
Symptoms
Common symptoms when B0704 is present:
- The check engine light is illuminated, typically remaining on until the issue is resolved. This is a primary indicator for many drivers.
- Drivers may experience erratic shifting patterns, where the transmission shifts unexpectedly or fails to shift at all, making driving hazardous.
- Fuel economy may suffer significantly, with reports of a 15-20% decrease, largely due to improper transmission operation.
- The vehicle may enter limp mode, which restricts engine power and limits driving ability, forcing drivers to seek immediate repairs.
- Some drivers report unusual noises from the transmission area, such as grinding or whining, indicating possible internal damage.
Possible Causes
Most common causes of B0704 (ordered by frequency):
- The most common cause of code B0704 is a faulty Transmission Range Sensor, which accounts for approximately 60% of cases. This sensor can fail due to wear and tear over time.
- Wiring issues, such as damaged or corroded connectors, can also trigger this code, making up about 25% of cases. Inspecting the wiring and connections for any visible damage is crucial.
- Another potential cause is low transmission fluid levels or dirty fluid, which can affect sensor performance. Regular maintenance can prevent this issue.
- Less common but serious causes include internal transmission problems, such as a failure in the valve body, which may require extensive repair.
- In rare cases, a faulty engine control module (ECM) can misinterpret the sensor signals, leading to the triggering of code B0704.
B0704 Repair Costs
Cost Breakdown by Repair Type
Transmission Range Sensor Replacement
Replacing the faulty Transmission Range Sensor with a new OEM part.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring and connectors related to the sensor.
- Total: $100 - $200
- Success rate: 70%
Money-Saving Tips for B0704
- 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 B0704 Diagnosis Process
Follow these systematic steps to accurately diagnose B0704. 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 to test the Transmission Range Sensor’s output voltage and resistance (20-30 minutes)
Step 3: Component testing - Use a multimeter to test the Transmission Range Sensor’s output voltage and resistance (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of the transmission after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation of the transmission 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, including city and highway, to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions, including city and highway, to confirm repair success (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 Range Sensor Replacement on 2016 Honda Accord
Vehicle: 2016 Honda Accord, 75,000 miles
Problem: Customer reported erratic shifting and check engine light.
Diagnosis: Scanned the vehicle using the GeekOBD APP and confirmed the B0704 code. Inspected the Transmission Range Sensor and found it faulty.
Solution: Replaced the Transmission Range Sensor and cleared the codes.
Cost: $250 (parts: $150, labor: $100)
Result: Post-repair, the customer reported smooth shifting and no reoccurrence of the check engine light.
Case Study 2: Wiring Repair on 2017 Toyota Camry
Vehicle: 2017 Toyota Camry, 60,000 miles
Problem: Customer noticed the vehicle would not shift into drive and check engine light was on.
Diagnosis: Used the GeekOBD APP to retrieve B0704 and inspected the wiring harness, discovering corrosion.
Solution: Repaired the damaged wiring and connectors, ensuring proper connection.
Cost: $180 (parts: $80, labor: $100)
Result: After repairs, the vehicle shifted smoothly, and the code did not return.