AutoCodes – Pontiac – U0109 Pontiac

U0109 Pontiac Code - Lost Communication With Fuel Pump 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 Fuel Pump Control Module, Fuel Pump Control Module harness is open or shorted, Fuel Pump 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: U0109 Pontiac indicates Lost Communication With Fuel Pump Control Module .
Common causes: Common causes include Faulty Fuel Pump Control Module, Fuel Pump Control Module harness is open or shorted, Fuel Pump 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 2,318

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 Mar 29, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0109 Pontiac 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.

OBDII Code U0109 Pontiac - Lost Communication With Fuel Pump Control Module - AutoCodes.com — U0109 Pontiac Code - Lost Communication With Fuel Pump Control Module

What does this mean?

What are the Possible Causes of the DTC U0109 Pontiac?

Faulty Fuel Pump Control Module
Fuel Pump Control Module harness is open or shorted
Fuel Pump Control Module circuit poor electrical connection

How to Fix the DTC U0109 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 U0109 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.

Need more information about the U0109 Pontiac code?

Need more information on how to fix the U0109 Pontiac code? Get Access to Factory Service Manuals

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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 U0109 Pontiac Code

1. What are the common symptoms of OBDII code U0109 in a Pontiac related to lost communication with the fuel pump control module?

- Common symptoms include engine stalling, difficulty starting the vehicle, and a non-functional fuel pump.

2. What are the possible causes of the U0109 code in a Pontiac?

- The U0109 code can be triggered by issues such as damaged wiring, a faulty fuel pump control module, or a communication network problem.

3. How can I diagnose the cause of the U0109 code in my Pontiac?

- To diagnose the issue, you can perform a visual inspection of the wiring, check for loose connections, and use a scan tool to communicate with the fuel pump control module.

4. Is it safe to continue driving my Pontiac with the U0109 code present?

- It is not recommended to drive your vehicle with the U0109 code, as it can lead to fuel delivery issues and potentially leave you stranded.

5. Can I repair the U0109 code in my Pontiac myself, or do I need professional help?

- Depending on your expertise, you may be able to repair the U0109 code yourself by addressing wiring issues or replacing the fuel pump control module. However, seeking professional help is advisable for accurate diagnosis and repair.

6. How much does it typically cost to fix the U0109 code in a Pontiac?

- The cost to fix the U0109 code can vary depending on the underlying issue. Simple fixes like repairing wiring may cost less, while replacing the fuel pump control module can be more expensive.

7. Are there any preventive measures to avoid the U0109 code in a Pontiac?

- To help prevent the U0109 code, it's essential to maintain your vehicle's electrical system, address any wiring issues promptly, and follow the manufacturer's recommended maintenance schedule.

8. Can a faulty fuel pump cause the U0109 code in a Pontiac?

- Yes, a faulty fuel pump or fuel pump control module can lead to the U0109 code due to the loss of communication between the module and the vehicle's systems.

9. Will resetting the OBDII system clear the U0109 code in my Pontiac?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the U0109 code persists, it is likely to reappear.

10. How urgent is it to address the U0109 code in a Pontiac?

- It is essential to address the U0109 code promptly to prevent potential fuel pump failure, stalling, or starting issues that can affect the drivability and safety of your vehicle.