AutoCodes – GMC – U1901 GMC

U1901 GMC Code - Lost Communication With Infotainment Multifunction Switch Module

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Infotainment Multifunction Switch Module, Infotainment Multifunction Switch Module harness is open or shorted, Infotainment Multifunction Switch 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: U1901 GMC indicates Lost Communication With Infotainment Multifunction Switch Module.
Common causes: Common causes include Faulty Infotainment Multifunction Switch Module, Infotainment Multifunction Switch Module harness is open or shorted, Infotainment Multifunction Switch 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 826

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 Jun 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1901 GMC Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices 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 device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U1901 GMC - Lost Communication With Infotainment Multifunction Switch Module - AutoCodes.com — U1901 GMC Code - Lost Communication With Infotainment Multifunction Switch Module

What does this mean?

What are the Possible Causes of the DTC U1901 GMC?

Faulty Infotainment Multifunction Switch Module
Infotainment Multifunction Switch Module harness is open or shorted
Infotainment Multifunction Switch Module circuit poor electrical connection

How to Fix the DTC U1901 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 U1901 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 U1901 GMC Code

1. What are the common symptoms of OBDII code U1901 GMC?

- Common symptoms include the infotainment system not functioning properly, loss of communication with the multifunction switch module, and warning lights on the dashboard.

2. What causes the U1901 GMC code to trigger?

- This code is usually triggered by a communication error between the vehicle's electronic control modules and the infotainment multifunction switch module.

3. How can I diagnose the U1901 GMC code?

- Diagnosis involves using a diagnostic scanner to retrieve the trouble codes, checking for loose or damaged wiring connections, and testing the communication between modules.

4. Can a faulty battery cause the U1901 GMC code?

- Yes, a weak or faulty battery can sometimes cause communication issues between electronic control modules, leading to the U1901 code.

5. What are some repair tips for fixing the U1901 GMC code?

- Repair tips include checking and repairing any damaged wiring connections, resetting the modules by disconnecting the battery for a few minutes, and updating the vehicle's software.

6. Is it safe to continue driving with the U1901 GMC code present?

- It is generally not recommended to continue driving with the U1901 code present, as it may affect the functionality of important systems in the vehicle.

7. Can a DIY enthusiast fix the U1901 GMC code at home?

- Some simple repairs, like checking and securing wiring connections, can be done by DIY enthusiasts. However, more complicated diagnostics and repairs may require professional help.

8. How much does it typically cost to repair the U1901 GMC code?

- The cost of repairing the U1901 code can vary depending on the underlying cause. It can range from a simple fix like tightening a loose connection to more complex repairs involving module replacements.

9. Will resetting the U1901 GMC code make it go away permanently?

- Resetting the code may clear it temporarily, but if the underlying issue is not addressed, the code is likely to reappear. It's important to diagnose and fix the root cause of the problem.

10. Can extreme weather conditions contribute to the U1901 GMC code?

- Yes, extreme weather conditions such as excessive heat or moisture can sometimes affect the electronic components in the vehicle, leading to communication errors and triggering the U1901 code.