AutoCodes – Generic – U016B

U016B Code - Lost Communication With Electric A/C Compressor Control Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Electric A/C Compressor Control Module, Electric A/C Compressor Control Module harness is open or shorted, Electric A/C Compressor 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: U016B indicates Lost Communication With Electric A/C Compressor Control Module.
Common causes: Common causes include Faulty Electric A/C Compressor Control Module, Electric A/C Compressor Control Module harness is open or shorted, Electric A/C Compressor 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 4,237

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 Apr 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U016B Description

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Electric A/C Compressor Control Module has not been received.

OBDII Code U016B - Lost Communication With Electric A/C Compressor Control Module - AutoCodes.com — U016B Code - Lost Communication With Electric A/C Compressor Control Module

What does this mean?

What are the Possible Causes of the DTC U016B?

Faulty Electric A/C Compressor Control Module
Electric A/C Compressor Control Module harness is open or shorted
Electric A/C Compressor Control Module circuit poor electrical connection

How to Fix the DTC U016B?

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 U016B 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 U016B code?

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Information for Specific Makes

U016B Buick — Lost Communication With Electric A/C Compressor Control Module
U016B Cadillac — Lost Communication With Electric A/C Compressor Control Module
U016B Chevrolet — Lost Communication With Electric A/C Compressor Control Module
U016B GMC — Lost Communication With Electric A/C Compressor 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 U016B Code

What does OBDII code U016B mean?

OBDII code U016B indicates a "Lost Communication With Electric A/C Compressor Control Module," meaning that the vehicle's control module is not receiving signals from the A/C compressor control module.

What are common symptoms of the U016B code?

Common symptoms include the air conditioning not functioning, erratic A/C operation, and a warning light on the dashboard indicating a fault.

What can cause the U016B code to trigger?

Causes can include a faulty A/C compressor control module, damaged wiring or connectors, or issues with the vehicle's main control module.

How can I diagnose the U016B code?

To diagnose the U016B code, use an OBDII scanner to confirm the code, check for other related codes, inspect wiring and connectors, and test the A/C compressor control module for proper operation.

What repairs might be needed for the U016B code?

Repairs may involve replacing the A/C compressor control module, repairing or replacing damaged wiring or connectors, or reprogramming the control module if necessary.

Can a low refrigerant level cause the U016B code?

While low refrigerant levels can affect A/C performance, they typically do not directly cause the U016B code, which is specifically related to communication issues.

Is it safe to drive a vehicle with the U016B code?

It is generally not advisable to drive a vehicle with the U016B code as it indicates a malfunction in the A/C system, which could lead to further issues or discomfort.

How can I prevent the U016B code from reoccurring?

To prevent the U016B code from reoccurring, regularly maintain your vehicle's A/C system, check wiring and connectors for damage, and ensure the control module is functioning properly.

Should I reset the code after repairs?

Yes, after making the necessary repairs, it is advisable to clear the code using an OBDII scanner and then test drive the vehicle to ensure the issue has been resolved.