AutoCodes – Pontiac – P1819 Pontiac

P1819 Pontiac 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 Pontiac 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 5,366

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 Sep 21, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1819 Pontiac Description

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

What does this mean?

What are the Possible Causes of the DTC P1819 Pontiac?

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 Pontiac?

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 Pontiac 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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Need more information on how to fix the P1819 Pontiac 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 P1819 Pontiac Code

1. What does the OBDII code P1819 mean on a Pontiac?

P1819 indicates an issue with the Internal Mode Switch (IMS) in the transmission, which monitors gear selection and reports it to the powertrain control module (PCM).

2. What are the common symptoms of code P1819 in a Pontiac?

Symptoms may include erratic shifting, the transmission being stuck in one gear, failure to engage certain gears, or the check engine light being illuminated.

3. What causes the P1819 code to appear on a Pontiac?

Common causes include a faulty Internal Mode Switch, damaged wiring or connectors in the IMS circuit, transmission fluid contamination, or a malfunctioning PCM.

4. Can driving with code P1819 damage the transmission in my Pontiac?

Yes, continuing to drive with this code can cause further damage to the transmission, as improper gear selection can lead to overheating or excessive wear.

5. How is the P1819 code diagnosed?

A mechanic will use a scan tool to confirm the code, inspect the IMS and its wiring for damage or corrosion, check the transmission fluid, and test the signal from the IMS to the PCM.

6. How do you fix the P1819 code on a Pontiac?

Repairs may involve replacing the Internal Mode Switch, repairing or replacing damaged wiring or connectors, performing a transmission fluid change, or in rare cases, reprogramming or replacing the PCM.

7. Is it expensive to fix the P1819 code on a Pontiac?

The cost depends on the repair. Replacing the Internal Mode Switch or repairing wiring is usually less expensive than replacing the PCM or addressing internal transmission damage.

8. Can low transmission fluid cause the P1819 code on a Pontiac?

Yes, low or contaminated transmission fluid can affect the operation of the Internal Mode Switch and trigger this code.

9. Do I need to replace the transmission to fix code P1819 on my Pontiac?

In most cases, replacing the entire transmission is unnecessary. The issue is typically localized to the IMS, wiring, or fluid.

10. How can I prevent the P1819 code from returning on my Pontiac?

Regularly check and maintain your transmission fluid, inspect wiring and connections for damage, and address any transmission issues promptly to prevent further problems.