AutoCodes – Chevrolet – P0633 2018 Chevrolet Silverado

P0633 2018 Chevrolet Silverado Code - Immobilizer Key Not Programmed

Quick Answer

When learning the immobilizer data, as well as the challenge and response sequence, the Engine Control Module (ECM) is placed in learn mode. Common causes include Immobilizer Key not programmed to the vehicle, Faulty Immobilizer Key, Faulty ignition switch. 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: P0633 2018 Chevrolet Silverado indicates Immobilizer Key Not Programmed.
Common causes: Common causes include Immobilizer Key not programmed to the vehicle, Faulty Immobilizer Key, Faulty ignition switch.
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 373

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jul 16, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0633 2018 Chevrolet Silverado Description

When learning the immobilizer data, as well as the challenge and response sequence, the Engine Control Module (ECM) is placed in learn mode. The Diagnostic Trouble Code (DTC) P0633 will be set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the immobilizer data and challenge/response are learned, learn mode will be exited when the engine is successfully started. If the ECM does not exit learn mode, the DTC P0633 will remain current and indicate a fault.

OBDII Code P0633 2018 Chevrolet Silverado - Immobilizer Key Not Programmed - AutoCodes.com — P0633 2018 Chevrolet Silverado Code - Immobilizer Key Not Programmed

What does this mean?

What are the Possible Causes of the DTC P0633 2018 Chevrolet Silverado?

Immobilizer Key not programmed to the vehicle
Faulty Immobilizer Key
Faulty ignition switch

How to Fix the DTC P0633 2018 Chevrolet Silverado?

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 does this mean?

Code Tech Notes

DTC P0633 will clear upon a successful engine start. Any malfunction that will cause a no-start condition will prevent DTC P0633 from clearing. Prior to diagnosing DTC P0633, ensure that all power moving, and engine control systems are operating properly and all conditions that may cause a no-start have been corrected. Do not replace the Engine Control Module (ECM). Replacing the Engine Control Module will not correct the no-start condition.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0633 2018 Chevrolet Silverado 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 P0633 2018 Chevrolet Silverado code?

Need more information on how to fix the P0633 2018 Chevrolet Silverado 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 P0633 2018 Chevrolet Silverado Code

What does OBDII code P0633 mean on a 2018 Chevrolet Silverado?

Code P0633 indicates that the immobilizer key has not been programmed or there is a communication issue between the immobilizer system and the engine control module (ECM).

What are the symptoms of code P0633 in a 2018 Chevrolet Silverado?

Common symptoms include the inability to start the vehicle, a security warning light on the dashboard, and potentially stored trouble codes related to the immobilizer system.

What causes the P0633 code to appear in a 2018 Chevrolet Silverado?

Causes may include an unprogrammed or incorrect key, issues with the immobilizer system, a faulty ECM, or wiring/communication problems between the key, immobilizer, and ECM.

Can I drive my 2018 Chevrolet Silverado with a P0633 code?

No, typically you cannot drive the vehicle because the immobilizer system prevents the engine from starting if the key is not programmed or recognized.

How is the P0633 code diagnosed?

A technician will use a scan tool to confirm the code, inspect the key and immobilizer system, check for communication errors, and test the ECM and related wiring connections.

How can I fix the P0633 code on my 2018 Chevrolet Silverado?

The issue can often be resolved by programming the key using a compatible scan tool. If that doesnâ€™t work, further repairs to the immobilizer system, ECM, or wiring may be required.

Do I need a new key to resolve the P0633 code?

Not always. If the key is functional but unprogrammed, it can be reprogrammed. However, a damaged or incorrect key may need to be replaced.

Can a dead key fob battery cause the P0633 code?

No, a dead key fob battery typically does not cause this code. The P0633 code is related to programming, not a lack of power in the key fob.

How much does it cost to fix the P0633 code on a 2018 Chevrolet Silverado?

The cost varies depending on the issue but typically ranges from $100 to $300 for key programming or minor repairs. Complex issues with the ECM or immobilizer system may cost more.

Can I program the key for my 2018 Silverado myself?

Some basic key programming can be done with instructions from the ownerâ€™s manual, but more advanced programming or issues may require specialized equipment or dealership assistance.