AutoCodes – Pontiac – U1147 Pontiac

U1147 Pontiac Code - Lost Communication With Onstar

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Onstar, Onstar harness is open or shorted, Onstar 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: U1147 Pontiac indicates Lost Communication With Onstar.
Common causes: Common causes include Faulty Onstar, Onstar harness is open or shorted, Onstar 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 613

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 U1147 Pontiac 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) U1147 is set.

OBDII Code U1147 Pontiac - Lost Communication With Onstar - AutoCodes.com — U1147 Pontiac Code - Lost Communication With Onstar

What does this mean?

What are the Possible Causes of the DTC U1147 Pontiac?

Faulty Onstar
Onstar harness is open or shorted
Onstar circuit poor electrical connection

How to Fix the DTC U1147 Pontiac?

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 U1147 Pontiac 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 U1147 Pontiac Code

1. What are the common symptoms of OBDII code U1147 in a Pontiac indicating lost communication with Onstar?

- Common symptoms include the Onstar system not functioning properly, loss of communication with the Onstar module, and potential issues with other vehicle systems linked to Onstar.

2. What could be the main causes of the U1147 code in a Pontiac?

- The U1147 code typically indicates a communication error between the vehicle's onboard diagnostic system and the Onstar module. This can be caused by a faulty Onstar module, wiring issues, or a problem with the vehicle's computer system.

3. How can I diagnose the U1147 code in my Pontiac?

- Diagnosis involves using an OBDII scanner to read the code, checking the Onstar module for any visible damage, inspecting the wiring connections, and testing the vehicle's communication systems.

4. Is it safe to drive my Pontiac with the U1147 code present?

- It is generally safe to drive the vehicle with the U1147 code, but it is recommended to have the issue diagnosed and repaired as soon as possible to ensure proper functioning of the Onstar system and other related systems.

5. Can I repair the U1147 code in my Pontiac on my own?

- Depending on your skill level and access to tools, you may be able to address the U1147 code by checking and repairing any loose connections, replacing damaged wiring, or replacing the Onstar module if necessary. However, it is recommended to consult a professional mechanic for accurate diagnosis and repair.

6. Are there any quick fixes for the U1147 code in a Pontiac?

- Quick fixes may include checking and tightening any loose connections related to the Onstar system, ensuring the Onstar module is securely in place, and resetting the vehicle's computer system to clear the code temporarily.

7. Will the U1147 code cause any other issues in my Pontiac?

- While the U1147 code itself may not directly cause other issues, it can lead to the loss of important features provided by the Onstar system, such as emergency assistance, vehicle diagnostics, and remote services.

8. How much does it typically cost to repair the U1147 code in a Pontiac?

- The cost of repairing the U1147 code can vary depending on the specific cause of the communication error. It may involve simple fixes like reconnecting wires or more complex repairs like replacing the Onstar module, with costs ranging from a few hundred to over a thousand dollars.

9. Can the U1147 code be triggered intermittently in a Pontiac?

- Yes, the U1147 code can be triggered intermittently due to loose connections, temporary communication errors, or environmental factors affecting the Onstar system. It is important to address the issue promptly to prevent recurring problems.

10. How can I prevent the U1147 code from reoccurring in my Pontiac?

- To prevent the U1147 code from reoccurring, regularly inspect the Onstar system components for damage or wear, ensure proper wiring connections, and keep the vehicle's communication systems well-maintained.