AutoCodes – GMC – U156D GMC

U156D GMC Code - Chassis Control Module Lost Communication With Transmission Shift Lever On LIN Bus

Quick Answer

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. Common causes include Faulty Transmission Shift Lever, Transmission Shift Lever harness is open or shorted, Transmission Shift Lever 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: U156D GMC indicates Chassis Control Module Lost Communication With Transmission Shift Lever On LIN Bus.
Common causes: Common causes include Faulty Transmission Shift Lever, Transmission Shift Lever harness is open or shorted, Transmission Shift Lever 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 607

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jun 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U156D GMC Description

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. The serial data is transmitted over a LIN circuit between a master control module and other LIN devices within a particular subsystem. If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) will set when a supervised periodic message to the Chassis Control Module from the Transmission Shift Lever has not been received.

OBDII Code U156D GMC - Chassis Control Module Lost Communication With Transmission Shift Lever On LIN Bus - AutoCodes.com — U156D GMC Code - Chassis Control Module Lost Communication With Transmission Shift Lever On LIN Bus

What does this mean?

What are the Possible Causes of the DTC U156D GMC?

Faulty Transmission Shift Lever
Transmission Shift Lever harness is open or shorted
Transmission Shift Lever circuit poor electrical connection
Faulty Chassis Control Module

How to Fix the DTC U156D 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 U156D 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 U156D GMC Code

What does the OBDII code U156D mean for my GMC vehicle?

The U156D code indicates that the Chassis Control Module has lost communication with the Transmission Shift Lever on the LIN (Local Interconnect Network) Bus.

What are the common symptoms of the U156D code?

Common symptoms may include transmission shifting issues, inability to shift gears, warning lights on the dashboard, or the vehicle may enter limp mode.

What could cause the U156D code to trigger?

Possible causes include a faulty Chassis Control Module, a malfunctioning Transmission Shift Lever, wiring issues, poor connections, or faults in the LIN Bus communication.

How can I diagnose the U156D code effectively?

Start by checking for any loose or damaged wiring and connectors related to the Chassis Control Module and Transmission Shift Lever. Use a scan tool to confirm the code and look for additional related codes.

What are some repair tips for fixing the U156D code?

Repair tips include inspecting and repairing any damaged wiring, ensuring all connections are secure, testing the functionality of the Transmission Shift Lever, and possibly replacing the Chassis Control Module if it's determined to be faulty.

Is it safe to drive my vehicle if the U156D code is present?

It may not be safe to drive, as the vehicle could experience shifting issues or enter limp mode. Itâ€™s advisable to address the issue as soon as possible to avoid further complications.

Can I clear the U156D code and hope it doesn't return?

While you can clear the code, if the underlying issue is not fixed, the code is likely to return. It's important to diagnose and repair the root cause before clearing the code.

How much does it typically cost to repair issues related to the U156D code?

Repair costs can vary widely depending on the specific issue, ranging from simple wiring repairs to replacing modules, with costs potentially running from $100 to over $1,000.

Should I take my GMC to a dealership for U156D code repairs?

While dealerships have specialized knowledge and diagnostic tools, a qualified independent mechanic familiar with GMC vehicles can also effectively diagnose and repair the issue.