AutoCodes – GMC – P0800 2017 GMC Sierra

P0800 2017 GMC Sierra Code - Active Transfer Case Control Module Requested MIL Illumination

Quick Answer

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. Common causes include Check Active Transfer Case Control Module for codes, Faulty Active Transfer Case Control Module. 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: P0800 2017 GMC Sierra indicates Active Transfer Case Control Module Requested MIL Illumination.
Common causes: Common causes include Check Active Transfer Case Control Module for codes, Faulty Active Transfer Case Control Module.
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 283

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 Jul 15, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0800 2017 GMC Sierra Description

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. If a condition is detected, the module sets a Diagnostic Trouble Code (DTC) and sends a serial data message to the Engine Control Module (ECM). The ECM sets a DTC to inform that the module has set a DTC. The serial data message sent by the module also contains a request for the ECM to illuminate the Malfunction Indicator Lamp (MIL).
The DTC will be set when the ECM receives a serial data message from the Active Transfer Case Control Module indicating that DTC has been set in the module.

OBDII Code P0800 2017 GMC Sierra - Active Transfer Case Control Module Requested MIL Illumination - AutoCodes.com — P0800 2017 GMC Sierra Code - Active Transfer Case Control Module Requested MIL Illumination

What does this mean?

What are the Possible Causes of the DTC P0800 2017 GMC Sierra?

Check Active Transfer Case Control Module for codes
Faulty Active Transfer Case Control Module

How to Fix the DTC P0800 2017 GMC Sierra?

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 P0800 2017 GMC Sierra 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 P0800 2017 GMC Sierra code?

Need more information on how to fix the P0800 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0800 2017 GMC Sierra Code

1. What does the OBDII code P0800 mean on a 2017 GMC Sierra?

P0800 indicates that the Active Transfer Case Control Module has requested the Malfunction Indicator Lamp (MIL) to illuminate, typically due to a fault in the transfer case or related systems.

2. What are the common symptoms of the P0800 code in a 2017 GMC Sierra?

Common symptoms include the check engine light being illuminated, issues with 4WD engagement, unusual noises from the transfer case, or the inability to switch between 2WD and 4WD modes.

3. What causes the P0800 code to appear on a 2017 GMC Sierra?

The code can be triggered by a faulty transfer case control module, damaged wiring or connectors, low or contaminated transfer case fluid, or a malfunctioning shift motor.

4. Can the P0800 code affect drivability in a 2017 GMC Sierra?

Yes, it can impact drivability if the vehicle is unable to properly engage or disengage 4WD, potentially leading to handling issues or reduced performance.

5. How is the P0800 code diagnosed in a 2017 GMC Sierra?

Diagnosis involves scanning for trouble codes, inspecting wiring and connectors for damage, testing the transfer case control module and shift motor, and checking the condition and level of the transfer case fluid.

6. Can I still drive my 2017 GMC Sierra with the P0800 code?

While it may be drivable, continued use without addressing the issue can lead to further damage to the transfer case system and compromise vehicle performance.

7. What repairs are typically needed to fix the P0800 code in a 2017 GMC Sierra?

Repairs may include replacing the transfer case control module, repairing or replacing damaged wiring, servicing the transfer case fluid, or replacing the transfer case shift motor.

8. How much does it cost to fix the P0800 code on a 2017 GMC Sierra?

Repair costs can vary widely, ranging from $100 for simple wiring repairs to $1,000 or more for transfer case module or shift motor replacements, depending on parts and labor.

9. Can a software update fix the P0800 code on a 2017 GMC Sierra?

In some cases, a software update for the transfer case control module may resolve the issue if the problem is related to a programming error.

10. How can I prevent the P0800 code from returning on my 2017 GMC Sierra?

Regular maintenance of the transfer case, including fluid checks and timely repairs of any 4WD system issues, can help prevent the P0800 code from recurring.