U0120 Mercury Code - Lost Communication With Starter/Generator Control Module
Quick Answer
The U0120 diagnostic trouble code (DTC) for Mercury vehicles indicates that there is a communication issue between the vehicle's engine control module (ECM) and the starter/generator control module. Common causes include Faulty starter/generator control module, Loose or corroded electrical connections between modules, Damaged wiring harness. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- U0120 Mercury indicates Lost Communication With Starter/Generator Control Module.
- Common causes
- Common causes include Faulty starter/generator control module, Loose or corroded electrical connections between modules, Damaged wiring harness.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code U0120 Mercury Description
The U0120 diagnostic trouble code (DTC) for Mercury vehicles indicates that there is a communication issue between the vehicle's engine control module (ECM) and the starter/generator control module. The starter/generator control module is responsible for managing the operation of the starter motor and generator in the vehicle. When communication is lost between these modules, it can lead to various performance issues and potentially affect the overall functionality of the vehicle.
Common Causes of U0120 Mercury
- Faulty starter/generator control module
- Loose or corroded electrical connections between modules
- Damaged wiring harness
- Software or programming issues within the ECM or control module
- Electrical interference or communication signal disruption
Symptoms of U0120 Mercury
- Difficulty starting the engine
- Battery not charging properly
- Illumination of the battery warning light on the dashboard
- Reduced fuel efficiency
- Engine stalling or hesitation during acceleration
How to Fix U0120 Mercury
- Begin by conducting a thorough inspection of the wiring harness and electrical connections between the ECM and starter/generator control module.
- Check for any loose or corroded connections and repair or replace them as necessary.
- Use a diagnostic scan tool to reset the codes and attempt to reestablish communication between the modules.
- If the issue persists, consider replacing the starter/generator control module or addressing any software-related issues through reprogramming or updates.
- Test the vehicle to ensure proper communication and functionality between the modules before finalizing the repair.
Cost to Fix U0120 Mercury
The typical repair costs for addressing a U0120 code on a Mercury vehicle can vary depending on the specific cause of the issue and the extent of the repairs needed. In general, the cost of parts for replacing a starter/generator control module can range from $200 to $500, while labor costs can add an additional $100 to $200. Overall, the total repair cost for resolving this communication error may fall within the range of $300 to $700. It's important to note that these estimates are approximate and can fluctuate based on factors such as location, vehicle model, and labor rates at auto repair shops. It is advisable to consult with a qualified mechanic or dealership to obtain a more accurate cost estimate for addressing the U0120 code on your Mercury vehicle.
Need more information about the U0120 Mercury code?
Need more information on how to fix the U0120 Mercury code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the U0120 Mercury code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about U0120 Mercury Code
1. What does the OBDII code U0120 mean on a Mercury?
U0120 indicates a loss of communication with the Starter/Generator Control Module (SGCM) on the vehicle's communication network.
2. What are the common symptoms of code U0120 in a Mercury?
Symptoms may include difficulty starting the vehicle, intermittent stalling, a no-crank condition, or the illumination of the check engine or warning lights.
3. What causes the U0120 code to appear on a Mercury?
Common causes include a faulty Starter/Generator Control Module, damaged wiring or connectors, network communication issues, or a low vehicle battery voltage.
4. Can a weak battery trigger the U0120 code on a Mercury?
Yes, a weak or failing battery can disrupt communication between modules and cause the U0120 code.
5. How do I diagnose the U0120 code on my Mercury?
Start by checking the battery voltage, inspecting the wiring and connectors to the SGCM, and using a scan tool to verify communication on the vehicle’s network.
6. Can I drive my Mercury with the U0120 code?
Driving with the U0120 code is not recommended, as it may lead to starting issues or other unexpected failures.
7. How is the U0120 code repaired on a Mercury?
Repairs may involve replacing or reprogramming the Starter/Generator Control Module, repairing damaged wiring, or resolving network communication faults.
8. Does the U0120 code mean the Starter/Generator Control Module is faulty?
Not necessarily. The issue could also stem from wiring problems, a weak battery, or other network communication issues.
9. How much does it cost to fix the U0120 code on a Mercury?
Repair costs vary but may range from $100 for basic wiring repairs to over $1,000 if the SGCM needs replacement or reprogramming.
10. Can a blown fuse cause the U0120 code on a Mercury?
Yes, a blown fuse related to the SGCM or communication network can cause the U0120 code to appear.
Discuss the causes and fixes for U0120 Mercury OBDII Code
Code U0120 Mercury comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.