AutoCodes – Saturn – U0140 Saturn

U0140 Saturn Code - Lost Communication With Body 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 Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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: U0140 Saturn indicates Lost Communication With Body Control Module.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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 9,091

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
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0140 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. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Body Control Module (BCM) has not been received.

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OBDII Code U0140 Saturn - Lost Communication With Body Control Module - AutoCodes.com — U0140 Saturn Code - Lost Communication With Body Control Module

What does this mean?

What are the Possible Causes of the DTC U0140 Saturn?

Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection

How to Fix the DTC U0140 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 U0140 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 U0140 Saturn Code

1. What are the common symptoms of OBDII code U0140 (Lost Communication With Body Control Module) in a Saturn?

- Common symptoms include issues with power windows, door locks, interior lights, and other body control functions not working properly.

2. What are the likely causes of OBDII code U0140 in a Saturn?

- The code U0140 usually indicates a communication problem between the Body Control Module (BCM) and the rest of the vehicle's systems. This can be caused by a faulty BCM, wiring issues, or a weak battery.

3. How can I diagnose the cause of OBDII code U0140 in my Saturn?

- To diagnose the issue, you can start by checking the wiring connections to the BCM, inspecting for any damage or corrosion. You may also need to perform a thorough scan using an OBDII scanner to retrieve more specific diagnostic trouble codes (DTCs) related to the communication failure.

4. Can a weak battery cause OBDII code U0140 in a Saturn?

- Yes, a weak or failing battery can sometimes trigger the U0140 code due to insufficient power supply for proper communication between the BCM and other modules. It's recommended to test and replace the battery if needed.

5. What are some repair tips for fixing OBDII code U0140 in a Saturn?

- Repair tips may include checking and repairing any damaged wiring, ensuring proper grounds, and potentially reprogramming or replacing the BCM if necessary. It's also crucial to address any underlying issues that may have caused the communication failure.

6. Is it safe to continue driving my Saturn with OBDII code U0140 present?

- It is generally not recommended to drive the vehicle with the U0140 code active, as it may lead to further electrical malfunctions and safety hazards. It's best to address the issue promptly to prevent any potential risks.

7. Can I reset the OBDII code U0140 in my Saturn without fixing the underlying issue?

- While you can temporarily clear the code using an OBDII scanner, it's important to note that the problem will likely reoccur if the root cause is not addressed. Resetting the code without proper diagnosis and repair may lead to ongoing issues.

8. How much does it typically cost to repair OBDII code U0140 in a Saturn?

- The cost of repairing the U0140 code can vary depending on the underlying cause and the extent of the repairs needed. Costs may include parts, labor, and diagnostic fees, so it's advisable to consult a professional mechanic for an accurate estimate.

9. Can a DIY enthusiast fix OBDII code U0140 in a Saturn?

- While some basic troubleshooting steps can be performed by DIY enthusiasts, diagnosing and repairing the U0140 code may require advanced knowledge and specialized equipment. For more complex issues, it's recommended to seek assistance from a qualified mechanic.

10. How long does it take to repair OBDII code U0140 in a Saturn?

- The repair time for the U0140 code can vary depending on the specific cause and the complexity of the fix. Simple issues like a loose connection may be resolved quickly, while more intricate problems could take several hours or longer to diagnose and repair.