AutoCodes – GMC – C0398 2018 GMC Sierra

C0398 2018 GMC Sierra Code - Range Actuator Position - Range Position Correlation

Quick Answer

The Transfer Case Control Module always monitors the Gear Position Sensor signal circuit and the Transfer Case Range Actuator Position Sensor signal circuit. Common causes include Faulty Transfer Case Range Actuator Position Sensor, Transfer Case Range Actuator Position Sensor harness is open or shorted, Transfer Case Range Actuator Position Sensor 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: C0398 2018 GMC Sierra indicates Range Actuator Position - Range Position Correlation.
Common causes: Common causes include Faulty Transfer Case Range Actuator Position Sensor, Transfer Case Range Actuator Position Sensor harness is open or shorted, Transfer Case Range Actuator Position Sensor 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 213

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 12, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0398 2018 GMC Sierra Description

The Transfer Case Control Module always monitors the Gear Position Sensor signal circuit and the Transfer Case Range Actuator Position Sensor signal circuit. The signal voltage values are converted to degrees to determine the position of the transfer case. The Transfer Case Control Module continuously compares the position of the Transfer Case Range Actuator Position Sensor to that of the Gear Position Sensor. If the positions do not match within a pre-determined range, it is considered an error and a fault is set. The Transfer Case Range Actuator Position Sensor is a higher resolution sensor and is more accurate but requires the Gear Position Sensor for correlation check at ignition ON and during transfer case range changes. The Diagnostic Trouble Code (DTC) will be set when the Range Actuator Position Sensor and the Range Position Sensor are both showing valid positions but differ by greater than a predetermined amount when no range change is in progress. The Transfer Case Range Actuator Position Sensor, also known as the incremental position sensor, is part of the Transfer Case Motor. The Gear Position Sensor, also known as the Transfer Case Range Actuator Position Sensor, the Two/Four Wheel Drive Actuator Position Sensor, or the rotational position sensor.

OBDII Code C0398 2018 GMC Sierra - Range Actuator Position - Range Position Correlation - AutoCodes.com — C0398 2018 GMC Sierra Code - Range Actuator Position - Range Position Correlation

What does this mean?

What are the Possible Causes of the DTC C0398 2018 GMC Sierra?

Faulty Transfer Case Range Actuator Position Sensor
Transfer Case Range Actuator Position Sensor harness is open or shorted
Transfer Case Range Actuator Position Sensor circuit poor electrical connection
Faulty Transfer Case Range Actuator Position Sensor (part of the Transfer Case Motor or Transfer Case Two/Four Wheel Drive Actuator)
Faulty Transfer Case Control Module

How to Fix the DTC C0398 2018 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 C0398 2018 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 C0398 2018 GMC Sierra 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 C0398 2018 GMC Sierra Code

1. What does OBDII code C0398 for a 2018 GMC Sierra mean?

- This code indicates a Range Actuator Position - Range Position Correlation issue in the vehicle's transmission system.

2. What are the common symptoms of OBDII code C0398 in a 2018 GMC Sierra?

- Common symptoms include rough shifting, poor acceleration, transmission slipping, and possible stalling.

3. What are the possible causes of OBDII code C0398 in a 2018 GMC Sierra?

- Causes can include a faulty range actuator, damaged wiring or connectors, low transmission fluid levels, or a malfunctioning transmission control module.

4. How can I diagnose OBDII code C0398 in my 2018 GMC Sierra?

- Diagnosis typically involves using a scan tool to retrieve the code, checking the transmission fluid level and condition, inspecting wiring and connectors, and performing tests on the range actuator.

5. What repairs are typically needed for OBDII code C0398 in a 2018 GMC Sierra?

- Repairs may involve replacing the range actuator, repairing or replacing damaged wiring or connectors, ensuring proper transmission fluid levels, or reprogramming the transmission control module.

6. Can I drive my 2018 GMC Sierra with OBDII code C0398?

- It is not recommended to drive the vehicle with this code, as it can lead to further transmission damage and safety hazards. Seek professional help to diagnose and repair the issue.

7. How much does it cost to fix OBDII code C0398 in a 2018 GMC Sierra?

- The cost of repair can vary depending on the exact cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

8. Can OBDII code C0398 in a 2018 GMC Sierra cause other problems if left unresolved?

- Yes, ignoring this code can lead to more serious transmission issues, increased fuel consumption, and potential safety risks while driving.

9. Is OBDII code C0398 a common problem in 2018 GMC Sierra vehicles?

- While it may not be extremely common, this code can still occur in 2018 GMC Sierra models due to various factors affecting the transmission system.

10. How can I prevent OBDII code C0398 from appearing in my 2018 GMC Sierra in the future?

- Regular maintenance, timely transmission fluid changes, and addressing any warning signs promptly can help prevent issues like C0398 from occurring in your vehicle.