What Is OBD Code U0107?
Code U0107 is a network communication diagnostic trouble code that means your vehicle’s engine control module (ECM) or powertrain control module (PCM) has lost its ability to communicate with the throttle actuator control module. The throttle actuator control module is responsible for electronically controlling your vehicle’s throttle position based on commands from the main engine computer. When this communication link breaks, the engine cannot properly regulate fuel and air mixture, which can cause drivability issues and trigger this fault code.
What Does U0107 Mean?
U0107 is classified as a network communication code in the U-series of OBD-II diagnostic trouble codes. The “U” prefix indicates a network or communication issue rather than a sensor malfunction or emissions problem. Specifically, U0107 means the ECM/PCM is unable to receive or transmit data to the throttle actuator control module via the vehicle’s internal communication network (typically the CAN bus or similar protocol).
The throttle actuator control module is an electronic component that controls the electronic throttle body, which regulates airflow into the engine. Without proper communication between these two modules, the engine cannot respond correctly to driver input or maintain proper idle speed, resulting in reduced performance and safety concerns.
Common Symptoms of U0107
- Check Engine Light (CEL) – The primary indicator that code U0107 has been stored
- Throttle Response Issues – Delayed or unresponsive throttle when accelerating
- Rough Idle – Engine may idle roughly or inconsistently
- Reduced Power – Noticeable loss of engine power and acceleration
- Limp Mode – Vehicle may enter a safe mode with limited performance
- Stalling – Engine may stall at stops or during driving
- Difficulty Starting – Engine may be hard to start or slow to crank
- Erratic Idle Speed – RPMs may fluctuate unexpectedly at idle
- No Symptoms – In some cases, the code may be stored without noticeable drivability issues
Possible Causes of U0107 (Ranked by Frequency)
- Corroded or Loose Battery Terminals – Poor battery connection is one of the most common causes of communication codes. Corrosion on battery posts or loose cable connections can disrupt power to modules and communication networks.
- Damaged or Corroded Wiring Harness – The wiring that connects the ECM/PCM to the throttle actuator control module may be corroded, pinched, or damaged, interrupting the signal.
- Faulty Throttle Actuator Control Module – The module itself may be defective and unable to communicate with the main engine computer.
- Faulty Engine Control Module (ECM/PCM) – The main engine computer may have internal communication issues or be failing.
- Defective CAN Bus or Communication Network – The vehicle’s internal communication bus (CAN, LIN, or other protocol) may be malfunctioning.
- Bad Ground Connections – Poor grounding of modules or wiring can prevent proper communication signals.
- Blown Fuses or Relays – A blown fuse or relay in the throttle actuator circuit can cut power and communication to the module.
- Faulty Throttle Body – While less common, a defective electronic throttle body may prevent proper communication.
- Software or Firmware Issues – Outdated or corrupted module software may prevent proper communication protocols.
- Aftermarket Modifications – Improper installation of aftermarket components or tuning devices may disrupt communication networks.
Diagnostic Steps for U0107
Step 1: Inspect Battery and Connections
Start with the simplest potential fix. Turn off the engine and inspect the battery terminals for corrosion (white, blue, or green crusty buildup). Clean any corrosion using a wire brush and baking soda solution. Ensure both the positive and negative battery cables are tight and making good contact. A loose battery connection is responsible for many U0107 codes.
Step 2: Check for Obvious Wiring Damage
Visually inspect the wiring harness that connects to the throttle body and any visible connectors. Look for pinched wires, melted insulation, water damage, or corrosion. Pay special attention to areas near the engine bay where wires may be exposed to heat or moisture. If you find damaged wiring, it will need to be repaired or replaced.
Step 3: Inspect Connector Terminals
Locate the throttle actuator control module connector (usually near the throttle body). Carefully disconnect it and inspect the terminals for corrosion, bent pins, or loose contacts. Clean the connector with electrical contact cleaner if needed. Reconnect firmly and ensure it seats completely.
Step 4: Check Fuses and Relays
Consult your vehicle’s fuse box diagram (typically found in the owner’s manual or on the fuse box cover) to locate the fuses and relays related to the throttle actuator circuit. Check that all relevant fuses are intact and not blown. Test relays for proper operation if you have the appropriate equipment.
Step 5: Verify Ground Connections
Trace the ground wires from the throttle actuator control module and ECM/PCM to their ground points on the engine block or chassis. Ensure all ground connections are clean, tight, and free of corrosion. Poor grounding is a common cause of communication failures.
Step 6: Use a Diagnostic Scanner
Connect a professional OBD-II diagnostic scanner to read all stored and pending codes. Look for additional codes that may provide more specific information about the communication failure. Check for codes related to the throttle body, ECM, or other modules. This will help narrow down the root cause.
Step 7: Perform Module Communication Test
If you have access to advanced diagnostic equipment, perform a module communication test to verify that the ECM/PCM can establish communication with the throttle actuator control module. This test will confirm whether the issue is a communication network problem or a module failure.
Step 8: Check for Technical Service Bulletins (TSBs)
Search your vehicle’s manufacturer TSBs for known issues related to U0107 or throttle actuator communication problems. Many manufacturers have issued bulletins with specific repair procedures for this code on certain model years.
Step 9: Professional Diagnosis
If the above steps don’t resolve the issue, the problem likely involves a faulty module, ECM, or complex wiring issue that requires professional diagnostic equipment and expertise. Take your vehicle to a qualified technician or dealership for further diagnosis.
Repair Cost Estimates
The cost to repair code U0107 varies significantly depending on the root cause:
- Battery Terminal Cleaning: $0-$50 (DIY) or $50-$150 (at a shop)
- Wiring Repair or Replacement: $150-$500 depending on extent of damage
- Throttle Actuator Control Module Replacement: $300-$800 including labor
- Engine Control Module (ECM/PCM) Replacement: $800-$2,500+ including programming
- Connector or Relay Replacement: $100-$400
- Complete Diagnostic Service: $100-$200 at a dealership
The most common repairs (battery cleaning and wiring fixes) are relatively inexpensive. However, if the throttle actuator control module or ECM needs replacement, costs can escalate quickly. Always get a detailed estimate before authorizing repairs.
Can I Still Drive With Code U0107?
Severity: Moderate to High
While you may be able to drive short distances with code U0107, it’s not recommended for extended driving. Here’s what you need to know:
- Limp Mode: Your vehicle will likely enter a reduced-power or “limp mode” to protect the engine, making acceleration sluggish and top speed limited.
- Safety Risk: Unpredictable throttle response can be dangerous, especially in traffic or highway driving where quick acceleration may be needed.
- Stalling Risk: The engine may stall unexpectedly, which is hazardous if it occurs in traffic.
- Further Damage: Driving with a communication failure could potentially cause additional damage to the engine or transmission if not addressed promptly.
- Emissions: The vehicle will likely fail an emissions test with this code active.
Recommendation: Have the code diagnosed and repaired as soon as possible. If you must drive the vehicle, do so cautiously and avoid highway driving. Start with the simple fixes (battery cleaning, connector inspection) before considering expensive module replacements.
Frequently Asked Questions About U0107
Q: Can a loose gas cap cause code U0107?
A: No, a loose gas cap typically causes code P0457 (evaporative emissions leak). However, a loose battery terminal can cause U0107, so if you recently had work done on your battery, that’s a good place to start troubleshooting.
Q: Will clearing code U0107 fix the problem?
A: Clearing the code without fixing the underlying problem is not a solution. The code will return once the vehicle is driven. You must identify and repair the root cause (wiring, module, connection, etc.) for a permanent fix.
Q: Is code U0107 the same as a throttle body problem?
A: Not necessarily. U0107 indicates a communication problem with the throttle actuator control module, not necessarily a failure of the throttle body itself. The throttle body may be functioning fine, but the ECM cannot communicate with its control module. However, a faulty throttle body could be the underlying cause in some cases.
Q: Can I drive to a mechanic with code U0107?
A: You can drive short distances to a mechanic, but proceed cautiously. The vehicle may have reduced power, rough idle, or stalling issues. Avoid highway driving if possible, as unpredictable throttle response can be dangerous at higher speeds. If the vehicle is severely affected, have it towed instead.
Q: How much does it cost to replace the throttle actuator control module?
A: Throttle actuator control module replacement typically costs $300-$800 including labor, depending on your vehicle’s make and model. Some vehicles have the module integrated into the throttle body, which can cost more to replace. Always get a specific quote from your mechanic or dealership.