AutoCodes – Saturn – U2105 Saturn

U2105 Saturn Code - Lost Communications with Engine Control Module

Quick Answer

Modules connected to the Controller Area Network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine 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: U2105 Saturn indicates Lost Communications with Engine Control Module.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine 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 873

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 18, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U2105 Saturn Description

Modules connected to the Controller Area Network (CAN) 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. The messages are supervised and also, and some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module. A module with a CAN serial data circuit malfunction or which loses power during the current ignition cycle will have a Loss of Communication Diagnostic Trouble Code (DTC) set by other modules that depend on information from that failed module. If any of the CAN circuits are shorted to battery voltage, ground, or between them no communication is possible on the CAN serial data bus, a DTC will be set.

OBDII Code U2105 Saturn - Lost Communications with Engine Control Module - AutoCodes.com — U2105 Saturn Code - Lost Communications with Engine Control Module

What does this mean?

What are the Possible Causes of the DTC U2105 Saturn?

Faulty Engine Control Module (ECM)
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection

How to Fix the DTC U2105 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 U2105 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.

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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 U2105 Saturn Code

1. What are the common symptoms of OBDII code U2105 (Lost Communications with Engine Control Module) in a Saturn?

- Common symptoms include loss of communication with the engine control module, engine stalling, rough idling, and issues with starting the vehicle.

2. What are some possible causes of OBDII code U2105 in a Saturn?

- Possible causes include a faulty engine control module (ECM), damaged wiring or connectors, software issues, or a malfunctioning communication network within the vehicle.

3. How can I diagnose the issue when experiencing OBDII code U2105 in my Saturn?

- A diagnostic scan tool can be used to retrieve the code and further diagnose the communication issue. Checking the wiring and connectors for damage or corrosion is also recommended.

4. Can I continue driving my Saturn with the U2105 code present?

- It is not recommended to continue driving with the U2105 code present, as it can lead to potential engine performance issues and safety concerns. It's best to address the issue promptly.

5. How can I repair OBDII code U2105 in my Saturn?

- Repairing the U2105 code may involve replacing the engine control module, repairing damaged wiring or connectors, updating software, or resetting the communication network in the vehicle.

6. Are there any DIY tips for troubleshooting OBDII code U2105 in a Saturn?

- DIY tips include checking for loose connections, inspecting wiring for damage, and ensuring the engine control module is securely in place. However, professional diagnosis and repair may be necessary.

7. Will resetting the OBDII code U2105 clear the issue in my Saturn?

- Resetting the code may temporarily clear the issue, but if the underlying problem causing the communication loss is not addressed, the code is likely to reappear. It's important to diagnose and repair the root cause.

8. Is it common for Saturn vehicles to experience OBDII code U2105 (Lost Communications with ECM)?

- While not extremely common, OBDII code U2105 can occur in Saturn vehicles due to various factors such as age, mileage, and electronic system malfunctions.

9. Can a simple battery disconnect fix OBDII code U2105 in a Saturn?

- A battery disconnect may reset the system and temporarily clear the code, but if the communication issue persists, further diagnosis and repair are recommended to fully address the problem.

10. How much does it typically cost to repair OBDII code U2105 in a Saturn?

- The cost of repairing OBDII code U2105 can vary depending on the specific issue causing the communication loss. Costs may range from a few hundred to over a thousand dollars, including parts and labor.