AutoCodes – Cadillac – P1823 Cadillac

P1823 Cadillac Code - Internal Mode Switch Circuit 'P' Low

Quick Answer

With the engine runtime over 5 seconds, system voltage from 8-18v, Fuel Cutoff inactive, engine torque from 30-148 ft-lb (40-200 Nm), the Powertrain Control Module (PCM) received an Internal Mode Switch (IMS) signal indicating PARK for 2 seconds, and then the IMS indicated a transitional state between Neutral and D4, conditions met for 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: P1823 Cadillac indicates Internal Mode Switch Circuit 'P' Low.
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 3,550

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 P1823 Cadillac Description

OBDII Code P1823 Cadillac - Internal Mode Switch Circuit 'P' Low - AutoCodes.com — P1823 Cadillac Code - Internal Mode Switch Circuit 'P' Low

What does this mean?

What are the Possible Causes of the DTC P1823 Cadillac?

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

How to Fix the DTC P1823 Cadillac?

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 P1823 Cadillac 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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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 P1823 Cadillac Code

1. What does the OBDII code P1823 mean on a Cadillac?

P1823 indicates an issue with the Internal Mode Switch Circuit 'P' Low, which monitors the position of the transmission range selector.

2. What are the common symptoms of code P1823 in a Cadillac?

Symptoms may include difficulty shifting gears, the transmission stuck in one gear, or the check engine light illuminating.

3. What causes the P1823 code to appear on a Cadillac?

Common causes include a faulty internal mode switch, damaged wiring or connectors in the circuit, or a malfunctioning transmission control module (TCM).

4. Can driving with the P1823 code damage my Cadillac?

Driving with this code may lead to transmission issues, reduced performance, and potential long-term damage if not addressed promptly.

5. How do you diagnose the P1823 code in a Cadillac?

Diagnosis involves scanning for codes, inspecting wiring and connectors in the circuit, and testing the internal mode switch functionality.

6. How is the P1823 code typically repaired on a Cadillac?

Repairs may involve replacing the internal mode switch, fixing damaged wiring or connectors, or reprogramming or replacing the TCM.

7. Is the P1823 code specific to Cadillac vehicles?

While common in Cadillacs, this code can appear in other GM vehicles equipped with similar transmission systems.

8. How much does it cost to repair the P1823 code on a Cadillac?

Repair costs vary but can range from $200 to $800, depending on whether the internal mode switch or other components need replacement.

9. Can a faulty internal mode switch cause other transmission codes to appear?

Yes, a malfunctioning switch can cause related codes indicating gear position or transmission control issues.

10. Do I need professional help to fix the P1823 code on my Cadillac?

While some fixes like inspecting wiring may be DIY-friendly, most repairs require specialized tools and expertise, so consulting a professional is recommended.