Quick Answer
U0705 means: U0705 indicates a communication failure between the Transmission Control Module and the Engine Control Module.
Can I drive with U0705? Immediate attention is recommended to prevent further damage to the transmission system.
Common Questions
What does U0705 mean and how does it affect my car?
The U0705 code signals a communication breakdown between the Transmission Control Module and the Engine Control Module, which can lead to severe transmission problems. If ignored, it may result in erratic shifting or complete transmission failure.
What are the most common causes of U0705 and how much does it cost to fix?
The most frequent cause is a faulty Transmission Control Module, with repair costs ranging from $300 to $700. Damaged wiring or connectors may also be to blame, costing between $100 and $300 to repair.
Can I drive my car with U0705 or should I stop immediately?
While it's technically possible to drive with a U0705 code, it's not advisable. The risk of transmission failure increases, and you may experience unsafe driving conditions. It’s best to address the issue promptly.
How can I diagnose U0705 myself using GeekOBD APP?
To diagnose U0705 using the GeekOBD APP, connect the device to your vehicle's OBD2 port and run a full scan. Check for any additional codes and review freeze frame data to understand the context of the fault.
What vehicles are most commonly affected by U0705?
Commonly affected vehicles include the 2006-2018 Ford Fusion, 2006-2018 Chrysler 300, and various models from Dodge and Jeep during this time frame. Check for any recalls related to transmission issues as well.
How can I prevent U0705 from happening again?
Regular maintenance, including checking transmission fluid levels and inspecting wiring connections, can help prevent U0705. Additionally, ensuring software updates for your vehicle's ECM can mitigate communication issues.
What is U0705?
The U0705 diagnostic trouble code (DTC) indicates a communication problem between the Transmission Control Module (TCM) and the Engine Control Module (ECM). It typically surfaces in vehicles from manufacturers like Ford and Chrysler, particularly models produced between 2006 and 2018. When the TCM cannot communicate effectively with the ECM, it can lead to various transmission issues, such as erratic shifting, reduced power, or even a complete failure to shift. This code suggests that the TCM is receiving incorrect data or is unable to transmit its data to the ECM effectively. Drivers may notice the check engine light illuminating, which serves as an early warning signal. If left unaddressed, this communication failure can lead to more severe transmission problems, resulting in costly repairs. The significance of promptly diagnosing and addressing a U0705 code cannot be overstated; ignoring it could lead to a complete transmission failure, significantly impacting vehicle performance and safety.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0705 is present:
- The check engine light stays on constantly, indicating a persistent issue that requires diagnostic attention.
- Engine hesitates during acceleration; drivers may experience unexpected shifts or loss of power, affecting overall driving comfort.
- Fuel economy decreased by 10-15%, as the vehicle may struggle to shift properly and utilize fuel efficiently.
- Transmission may shift erratically or fail to shift at all, leading to a potentially dangerous situation while driving.
- Unusual noises from the transmission, such as grinding or clunking, which can indicate underlying mechanical issues.
Possible Causes
Most common causes of U0705 (ordered by frequency):
- The most common cause of the U0705 code is a faulty Transmission Control Module, with a likelihood of about 40%. This could stem from internal failure or external wiring issues.
- A second common cause is damaged wiring or connectors in the communication circuit, which may occur due to wear and tear or exposure to environmental factors.
- Thirdly, a low transmission fluid level can impact the TCM's ability to function correctly, making regular fluid checks essential for prevention.
- Less common but serious causes include a faulty Engine Control Module, which can significantly disrupt communication between the modules.
- Rarely, software glitches in the vehicle's onboard computer systems can lead to the U0705 code, necessitating a software update.
U0705 Repair Costs
Cost Breakdown by Repair Type
TCM Replacement
Replacing the Transmission Control Module can resolve the communication issues.
- Total: $300 - $700
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring or connectors related to the TCM.
- Total: $100 - $300
- Success rate: 75%
Money-Saving Tips for U0705
- 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 U0705 Diagnosis Process
Follow these systematic steps to accurately diagnose U0705. 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 suspected components such as the TCM and associated connectors (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components such as the TCM and associated connectors (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes to check for reoccurrence (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes to check for reoccurrence (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure all systems are functioning properly (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure all systems are functioning properly (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 Control Module Replacement in a 2014 Ford Fusion
Vehicle: 2014 Ford Fusion, 85,000 miles
Problem: Customer reported erratic shifting and check engine light illuminated.
Diagnosis: After scanning with OBD2, U0705 was confirmed. A visual inspection revealed damaged TCM wiring.
Solution: Replaced the TCM and repaired wiring connections.
Cost: $650 (including parts and labor)
Result: The vehicle operated smoothly post-repair, with no further issues reported.
Case Study 2: Wiring Repair for a 2015 Chrysler 300
Vehicle: 2015 Chrysler 300, 72,000 miles
Problem: Customer experienced loss of power during acceleration.
Diagnosis: Diagnostic tests confirmed U0705. Inspection found corroded wiring connectors.
Solution: Repaired connectors and cleared the fault codes.
Cost: $150 (including parts and labor)
Result: The vehicle regained normal performance and the check engine light remained off.