AutoCodes – GMC – U1152 GMC

U1152 GMC Code - Lost Communications With HVAC Control Module

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module, HVAC Control Module harness is open or shorted, HVAC 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: U1152 GMC indicates Lost Communications With HVAC Control Module .
Common causes: Common causes include Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module, HVAC Control Module harness is open or shorted, HVAC 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 2,930

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 24, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1152 GMC Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for the state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a Diagnostic Trouble Code (DTC) U1152 is set.

OBDII Code U1152 GMC - Lost Communications With HVAC Control Module - AutoCodes.com — U1152 GMC Code - Lost Communications With HVAC Control Module

What does this mean?

What are the Possible Causes of the DTC U1152 GMC?

Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
HVAC Control Module harness is open or shorted
HVAC Control Module circuit poor electrical connection

How to Fix the DTC U1152 GMC?

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 U1152 GMC 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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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 U1152 GMC Code

1. What does the OBDII code U1152 mean on a GMC vehicle?

Code U1152 indicates a loss of communication between the HVAC control module and other modules on the vehicle's communication network.

2. What are the common symptoms of the U1152 code on a GMC?

Symptoms can include non-functional HVAC controls, inability to adjust temperature or fan speed, and the HVAC system operating erratically.

3. What causes the U1152 code to occur?

Common causes include a faulty HVAC control module, wiring issues such as damaged or corroded connectors, or a problem with the vehicleâ€™s communication network.

4. Can a weak battery cause the U1152 code on a GMC?

Yes, a weak or failing battery can disrupt communication between modules, potentially triggering the U1152 code.

5. How can I diagnose the U1152 code on my GMC?

Start by inspecting the HVAC module connections for damage or corrosion, then use a scan tool to check for other related codes and test the communication network.

6. Is it safe to drive with the U1152 code on a GMC?

Yes, but the HVAC system may not function properly, which can be inconvenient, especially in extreme weather conditions.

7. How do I fix the U1152 code on a GMC?

Repairs may involve cleaning or repairing wiring/connectors, reprogramming the HVAC control module, or replacing the module if itâ€™s defective.

8. Can the U1152 code be caused by a blown fuse?

Yes, a blown fuse related to the HVAC system or communication network can interrupt module communication, causing this code.

9. Do I need a professional to fix the U1152 code?

If basic inspections like checking fuses and wiring donâ€™t resolve the issue, itâ€™s best to consult a professional with the proper diagnostic tools.

10. Can software updates fix the U1152 code on a GMC?

In some cases, reprogramming or updating the software of the affected modules may resolve communication issues and clear the U1152 code.