U1806 Code - Battery Energy Control Module High Voltage Energy Management CAN Bus Off
Quick Answer
The high voltage energy management high-speed General Motor Local Area Network (GMLAN) serial data circuits are serial data buses used to communicate information between the Hybrid Powertrain Control Module 2, the Battery Energy Control Module, and the Battery Charger. Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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
- U1806 indicates Battery Energy Control Module High Voltage Energy Management CAN Bus Off.
- Common causes
- Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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.
Code U1806 Description
The scan tool does not communicate with devices through the high voltage energy management high-speed GMLAN bus. The high voltage energy high-speed GMLAN serial data circuits connect directly to the auxiliary data connector and do not connect with the scan tool.
The Diagnostic Trouble Code (DTC) will set when the device setting the DTC has attempted to establish communications on the serial data circuits for more than 1.4 seconds without success.
What are the Possible Causes of the DTC U1806?
- Faulty Battery Energy Control Module
- Battery Energy Control Module harness is open or shorted
- Battery Energy Control Module circuit poor electrical connection
- Faulty Hybrid Powertrain Control Module 2
How to Fix the DTC U1806?
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 U1806 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.
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Information for Specific Makes
- U1806 Buick — Battery Energy Control Module High Voltage Energy Management CAN Bus Off
- U1806 Cadillac — Battery Energy Control Module High Voltage Energy Management CAN Bus Off
- U1806 Chevrolet — Battery Energy Control Module High Voltage Energy Management CAN Bus Off
- U1806 GMC — Battery Energy Control Module High Voltage Energy Management CAN Bus Off
Frequently Asked Questions about U1806 Code
What does the OBDII code U1806 mean?
The U1806 code indicates a communication failure on the CAN bus network involving the Battery Energy Control Module and the High Voltage Energy Management system.
What are the common symptoms of code U1806?
Symptoms may include the check engine light or hybrid system warning light, reduced engine power, poor fuel efficiency, or the inability to start the vehicle.
What causes the U1806 code to appear?
Common causes include damaged or corroded CAN bus wiring, a faulty Battery Energy Control Module, a defective High Voltage Energy Management module, or issues with the CAN bus connections.
Can a weak battery cause the U1806 code?
Yes, a weak or failing 12-volt battery can lead to communication issues on the CAN bus network, potentially triggering the U1806 code.
How do you diagnose the U1806 code?
Diagnosis involves scanning for additional codes, inspecting CAN bus wiring and connectors for damage, testing the battery and charging system, and verifying module functionality with specialized diagnostic tools.
Can the U1806 code cause the vehicle to stop running?
Yes, in some cases, the U1806 code can result in the vehicle going into a fail-safe or limp mode, or it may prevent the vehicle from starting altogether.
How is the U1806 code fixed?
Repairs may include replacing damaged wiring or connectors, reprogramming or replacing faulty modules, or addressing power supply issues like a failing battery.
Is it safe to drive with the U1806 code active?
It is not recommended to drive with this code active, as it can lead to reduced performance or further damage to the vehicle's hybrid or electrical systems.
Can clearing the U1806 code solve the problem?
Clearing the code may temporarily remove the warning, but the underlying issue must be addressed to prevent the code from returning.
How much does it cost to fix the U1806 code?
Repair costs vary widely depending on the root cause, ranging from $100 for simple wiring fixes to over $1,000 for module replacements or complex electrical repairs.
Discuss the causes and fixes for U1806 OBDII Code
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