AutoCodes – Saturn – U0109 Saturn

U0109 Saturn 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 Saturn 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 4,569

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

What does this mean?

What are the Possible Causes of the DTC U0109 Saturn?

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 Saturn?

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 Saturn 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 Saturn code?

Need more information on how to fix the U0109 Saturn 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 Saturn Code

1. What are the common symptoms of OBDII code U0109 (Lost Communication With Fuel Pump Control Module) in a Saturn vehicle?

- Common symptoms include difficulty starting the vehicle, engine stalling, fuel pump issues, and the illumination of the check engine light.

2. What are the possible causes of OBDII code U0109 in a Saturn vehicle?

- The code U0109 can be triggered by issues such as a faulty fuel pump control module, wiring or connection problems, a malfunctioning fuel pump, or issues with the powertrain control module (PCM).

3. How can I diagnose the OBDII code U0109 in my Saturn vehicle?

- To diagnose code U0109, it is recommended to use an OBDII scanner to retrieve the code and perform a thorough inspection of the fuel pump control module, wiring connections, and related components.

4. Can I continue driving my Saturn with OBDII code U0109 present?

- It is not advisable to continue driving with code U0109 present, as it can lead to potential fuel delivery issues and engine performance problems. It is recommended to address the issue promptly.

5. How can I repair OBDII code U0109 in my Saturn vehicle?

- Repair options for code U0109 may include repairing or replacing the fuel pump control module, addressing any wiring issues, ensuring proper connections, and clearing the code using an OBDII scanner.

6. Are there any DIY tips for troubleshooting OBDII code U0109 in a Saturn vehicle?

- DIY tips may include checking the fuel pump control module fuse, inspecting wiring for damage, ensuring proper grounding, and checking for any loose connections.

7. Can a mechanic help with diagnosing and repairing OBDII code U0109 in my Saturn?

- Yes, a qualified mechanic can assist in diagnosing and repairing code U0109 by using specialized diagnostic tools, conducting thorough inspections, and performing necessary repairs.

8. How much does it typically cost to repair OBDII code U0109 in a Saturn vehicle?

- The cost of repairing code U0109 can vary depending on the underlying cause, the extent of the issue, and whether parts need to be replaced. Costs can range from a few hundred to over a thousand dollars.

9. Is the fuel pump control module a common issue in Saturn vehicles triggering code U0109?

- Yes, the fuel pump control module can be a common culprit for triggering code U0109 in Saturn vehicles, especially in older models or vehicles with high mileage.

10. How can I prevent OBDII code U0109 from occurring in my Saturn vehicle?

- To prevent code U0109, it's essential to maintain regular vehicle maintenance, address any fuel system issues promptly, and avoid driving with low fuel levels to reduce strain on the fuel pump control module.