AutoCodes – GMC – P1819 GMC

P1819 GMC Code - Internal Mode Switch

Quick Answer

With the key in Start (crank) position, system voltage from 9-18v, the Powertrain Control Module (PCM) detects an invalid combination of Internal Mode Switch signals, or a set of signals that indicated a transitional state between gear positions, condition met for 0.5 seconds. Common causes include Faulty Internal Mode Switch, Internal Mode Switch harness is open or shorted, Internal Mode Switch 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: P1819 GMC indicates Internal Mode Switch.
Common causes: Common causes include Faulty Internal Mode Switch, Internal Mode Switch harness is open or shorted, Internal Mode Switch 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 1,668

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 Sep 21, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
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Code P1819 GMC Description

OBDII Code P1819 GMC - Internal Mode Switch - AutoCodes.com — P1819 GMC Code - Internal Mode Switch

What does this mean?

What are the Possible Causes of the DTC P1819 GMC?

Faulty Internal Mode Switch
Internal Mode Switch harness is open or shorted
Internal Mode Switch circuit poor electrical connection

How to Fix the DTC P1819 GMC?

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 P1819 GMC 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 P1819 GMC 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.