AutoCodes – Cadillac – U0155 Cadillac

U0155 Cadillac Code - Lost Communication With Instrument Panel Cluster 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 Instrument Panel Cluster Control Module, Instrument Panel Cluster Control Module harness is open or shorted, Instrument Panel Cluster 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: U0155 Cadillac indicates Lost Communication With Instrument Panel Cluster Control Module.
Common causes: Common causes include Faulty Instrument Panel Cluster Control Module, Instrument Panel Cluster Control Module harness is open or shorted, Instrument Panel Cluster 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 2,922

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 01, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0155 Cadillac 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 Instrument Panel Cluster Control Module has not been received.

OBDII Code U0155 Cadillac - Lost Communication With Instrument Panel Cluster Control Module - AutoCodes.com — U0155 Cadillac Code - Lost Communication With Instrument Panel Cluster Control Module

What does this mean?

What are the Possible Causes of the DTC U0155 Cadillac?

Faulty Instrument Panel Cluster Control Module
Instrument Panel Cluster Control Module harness is open or shorted
Instrument Panel Cluster Control Module circuit poor electrical connection

How to Fix the DTC U0155 Cadillac?

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 U0155 Cadillac 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 U0155 Cadillac Code

1. What does the OBDII code U0155 mean on a Cadillac?

The U0155 code means the vehicle has lost communication with the instrument panel cluster (IPC) control module, which manages the display of vital information like speed, fuel level, and warning lights.

2. What are the common symptoms of the U0155 code on a Cadillac?

Symptoms may include a non-functional instrument cluster, blank or flickering displays, inoperative gauges, erratic warning lights, or difficulty starting the vehicle.

3. What causes the U0155 code to appear on a Cadillac?

The code can be caused by faulty wiring, a defective instrument panel cluster, a failed IPC control module, software issues, or problems with the CAN (Controller Area Network) bus communication system.

4. Can a dead battery cause the U0155 code on a Cadillac?

Yes, a dead or weak battery, as well as voltage issues, can disrupt communication between the modules and trigger the U0155 code.

5. How do you diagnose the U0155 code on a Cadillac?

Diagnosis involves scanning for related codes, inspecting the wiring and connectors to the IPC, testing the CAN bus communication, and verifying the power and ground supply to the control module.

6. Can I still drive my Cadillac with a U0155 code?

It is not recommended to drive with a U0155 code, as the loss of instrument cluster functionality can prevent you from monitoring critical vehicle information like speed and engine warnings.

7. How much does it cost to fix the U0155 code on a Cadillac?

The repair cost can vary widely, ranging from $100 for minor wiring repairs to over $1,000 if the instrument cluster or control module needs replacement.

8. Can I fix the U0155 code on my Cadillac myself?

If you have automotive electrical knowledge, you can inspect and repair loose connections or damaged wiring. However, diagnosing and replacing the IPC module usually requires professional tools and expertise.

9. Does the U0155 code require reprogramming the IPC control module?

In some cases, replacing the IPC or repairing related issues may require reprogramming the module with specialized diagnostic equipment.

10. What should I check first when troubleshooting the U0155 code on a Cadillac?

Start by checking the battery voltage, inspecting the wiring and connectors to the instrument cluster, and ensuring the CAN bus is functioning properly.