AutoCodes – Generic – U012D

U012D Code - Lost Communication With Generator Control Module

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Faulty Generator Control Module, Generator Control Module harness is open or shorted, Generator Control Module circuit poor electrical connection. 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: U012D indicates Lost Communication With Generator Control Module.
Common causes: Common causes include Faulty Generator Control Module, Generator Control Module harness is open or shorted, Generator Control Module circuit poor electrical connection.
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.

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Code Popularity 12,890

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 31, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U012D Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Generator Control Module has not been received.

OBDII Code U012D - Lost Communication With Generator Control Module - AutoCodes.com — U012D Code - Lost Communication With Generator Control Module

What does this mean?

What are the Possible Causes of the DTC U012D?

Faulty Generator Control Module
Generator Control Module harness is open or shorted
Generator Control Module circuit poor electrical connection

How to Fix the DTC U012D?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U012D code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U012D code?

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Need Help with the Code?

Get the U012D code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U012D Ford — Lost Communication With Generator Control Module
U012D Lincoln — Lost Communication With Generator Control Module
U012D Mercury — Lost Communication With Generator Control Module

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U012D Code

1. What are the common symptoms of OBDII code U012D (Lost Communication With Generator Control Module)?

- Common symptoms include issues with the vehicle's electrical system, such as dimming lights, battery problems, and irregular charging.

2. What are some possible causes of OBDII code U012D?

- The code U012D can be triggered by a faulty generator control module, damaged wiring or connectors, a weak battery, or issues with the communication network in the vehicle.

3. How can I diagnose the cause of OBDII code U012D?

- Diagnosing the cause of code U012D typically involves checking the generator control module, inspecting the wiring and connectors for damage, testing the battery's voltage, and using a diagnostic scanner to analyze the communication network.

4. Can I still drive my vehicle with OBDII code U012D?

- It is not recommended to drive the vehicle with code U012D as it can lead to potential electrical system failures and affect the overall performance of the vehicle.

5. How can I repair OBDII code U012D?

- Repairing code U012D may involve replacing the faulty generator control module, repairing or replacing damaged wiring and connectors, ensuring the battery is in good condition, and addressing any issues with the vehicle's communication network.

6. Will resetting the fault codes make OBDII code U012D go away?

- Resetting the fault codes may temporarily clear the code, but it is important to diagnose and repair the underlying issue triggering code U012D to prevent it from reoccurring.

7. Is it safe to ignore OBDII code U012D?

- Ignoring code U012D can lead to potential electrical system issues and may cause further damage to the vehicle, so it is not recommended to ignore this fault code.

8. Can a DIY enthusiast repair OBDII code U012D?

- Depending on the individual's skill level and access to tools, a DIY enthusiast may be able to diagnose and repair code U012D, but it is recommended to seek professional help for complex electrical system issues.

9. How much does it cost to fix OBDII code U012D?

- The cost of fixing code U012D can vary depending on the root cause of the issue, the extent of repairs needed, and labor costs at the repair shop. It is advisable to get estimates from multiple sources.

10. How can I prevent OBDII code U012D from occurring in the future?

- To prevent code U012D, it is essential to perform regular maintenance on the vehicle's electrical system, keep the battery in good condition, and address any warning signs of potential issues promptly.