AutoCodes – Generic – U0007

U0007 Code - High Speed CAN Communication Bus (-) Low

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module. 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: U0007 indicates High Speed CAN Communication Bus (-) Low.
Common causes: Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module.
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 8,257

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 29, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0007 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 supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U0007 - High Speed CAN Communication Bus (-) Low - AutoCodes.com — U0007 Code - High Speed CAN Communication Bus (-) Low

What does this mean?

What are the Possible Causes of the DTC U0007?

Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s)
Check for more codes
Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U0007?

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 U0007 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 U0007 code?

Need more information on how to fix the U0007 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0007 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U0007 Ford — High Speed CAN Communication Bus (-) Low
U0007 Lincoln — High Speed CAN Communication Bus (-) Low
U0007 Mercury — High Speed CAN Communication Bus (-) Low

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 U0007 Code

1. What are the common symptoms of OBDII code U0007 (High Speed CAN Communication Bus (-) Low)?

- Common symptoms include problems with the vehicle's communication systems, such as loss of communication between control modules, warning lights on the dashboard, and issues with various electronic components.

2. What are the possible causes of OBDII code U0007?

- Possible causes include damaged wiring or connectors in the CAN (Controller Area Network) communication system, a faulty control module, a short circuit in the network, or a malfunctioning CAN bus.

3. How can I diagnose OBDII code U0007?

- Diagnosing this code typically involves using a scan tool to identify the specific module or circuit that is causing the communication error. A thorough inspection of the wiring, connectors, and control modules in the CAN system is also necessary.

4. What are some repair tips for resolving OBDII code U0007?

- Repair tips may include checking and repairing any damaged wiring or connectors, replacing faulty control modules, ensuring proper grounding of the CAN bus system, and clearing the code after making necessary repairs.

5. Is it safe to continue driving with OBDII code U0007 present?

- It is not recommended to continue driving with this code present, as it can lead to further communication issues and potential malfunctions of critical vehicle systems. It is best to address the underlying problem promptly.

6. Can OBDII code U0007 be triggered by a loose connection in the CAN communication system?

- Yes, a loose or poor connection in the CAN communication system can disrupt the signal flow and trigger code U0007. Checking and securing all connections is an important step in diagnosing and repairing this issue.

7. Will resetting the OBDII code U0007 make it go away permanently?

- Resetting the code may temporarily clear the warning light, but if the underlying issue causing code U0007 is not addressed, the code is likely to reappear. It is crucial to diagnose and repair the root cause of the problem.

8. How do I prevent OBDII code U0007 from recurring in the future?

- To prevent the recurrence of this code, regular maintenance of the vehicle's communication systems and wiring is essential. Checking for loose connections, ensuring proper grounding, and addressing any potential issues promptly can help avoid future problems.

9. Can extreme weather conditions affect the occurrence of OBDII code U0007?

- Yes, extreme weather conditions, such as temperature fluctuations or exposure to moisture, can impact the stability of the CAN communication system and potentially trigger code U0007. Protecting the system from environmental factors is important.

10. Is it necessary to visit a professional mechanic for OBDII code U0007 diagnosis and repair?

- While some basic checks and repairs can be done by DIY enthusiasts, diagnosing and repairing OBDII code U0007 may require specialized tools and expertise. Consulting a professional mechanic is recommended for accurate diagnosis and effective resolution.