AutoCodes – Chevrolet – P0633 Chevrolet

P0633 Chevrolet 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 Chevrolet 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 25,213

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 17, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
Comments
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Code P0633 Chevrolet 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 Chevrolet - Immobilizer Key Not Programmed - AutoCodes.com — P0633 Chevrolet Code - Immobilizer Key Not Programmed

What does this mean?

What are the Possible Causes of the DTC P0633 Chevrolet?

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

How to Fix the DTC P0633 Chevrolet?

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.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0633 Chevrolet 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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Information for Specific Chevrolet Models

P0633 2014 Chevrolet Silverado — Immobilizer Key Not Programmed
P0633 2015 Chevrolet Silverado — Immobilizer Key Not Programmed
P0633 2016 Chevrolet Silverado — Immobilizer Key Not Programmed
P0633 2017 Chevrolet Silverado — Immobilizer Key Not Programmed
P0633 2018 Chevrolet Silverado — Immobilizer Key Not Programmed

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.