AutoCodes – Generic – P1825

P1825 Code - Internal Mode Switch Invalid Range

Quick Answer

The manual shift detent lever with shaft position switch assembly, or Internal Mode Switch (IMS) assembly is a sliding contact switch attached to the control valve body within the transmission. 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: P1825 indicates Internal Mode Switch Invalid Range.
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 39,284

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
FAQs
Comments
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Code P1825 Description

The manual shift detent lever with shaft position switch assembly, or Internal Mode Switch (IMS) assembly is a sliding contact switch attached to the control valve body within the transmission. The 4 inputs to the Transmission Control Module (TCM) from the switch indicate which position is selected by the transmission manual shaft. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The IMS input parameters represented are transmission range signal A, Signal B, signal C, and signal

OBDII Code P1825 - Internal Mode Switch Invalid Range - AutoCodes.com — P1825 Code - Internal Mode Switch Invalid Range

What does this mean?

What are the Possible Causes of the DTC P1825?

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

How to Fix the DTC P1825?

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 P1825 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 P1825 code?

Need more information on how to fix the P1825 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1825 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1825 Buick — Internal Mode Switch Invalid Range
P1825 Cadillac — Internal Mode Switch Invalid Range
P1825 Chevrolet — Internal Mode Switch Invalid Range
P1825 GMC — Internal Mode Switch Invalid Range
P1825 Mitsubishi — Shift Fork Position Sensor 2 System Voltage Low Range Out

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 P1825 Code

1. What does the OBDII code P1825 mean?

The P1825 code indicates that the Internal Mode Switch (IMS) in the transmission is reporting a range or position that is not logical or expected by the vehicle's control module.

2. What are common symptoms of the P1825 code?

Symptoms may include transmission slipping, harsh shifting, the transmission stuck in one gear, the vehicle not starting, or the engine stalling. The check engine light will also be illuminated.

3. What causes the P1825 code to be triggered?

This code can be triggered by a faulty internal mode switch, wiring issues related to the IMS (such as shorts or opens), or problems with the transmission control module (TCM).

4. How can I diagnose the P1825 code in my vehicle?

Diagnosis should begin with a visual inspection of the IMS and associated wiring for any obvious damage. Use a scan tool to monitor IMS operation and check for additional codes that could indicate related issues. Testing should include electrical continuity and resistance checks in the wiring harness.

5. What repairs can fix the P1825 code?

Repairs might include replacing the internal mode switch, repairing or replacing damaged wiring, or in some cases, reprogramming or replacing the transmission control module.

6. Is it safe to drive a vehicle with the P1825 code?

Driving with this code is not recommended as it can lead to transmission behaviors that might compromise vehicle safety or further damage the transmission.

7. What is the Internal Mode Switch and what does it do?

The Internal Mode Switch (IMS) is a component in automatic transmissions that provides information to the transmission control module about the current gear position or selected mode, aiding in proper gear selection and operation.

8. How urgent is it to address the P1825 code?

Addressing the P1825 code should be considered urgent to prevent potential safety issues and more costly repairs due to additional damage to the transmission system.

9. Can a faulty battery or alternator trigger the P1825 code?

While a faulty battery or alternator is less likely to directly cause this code, electrical issues, including low voltage conditions, can exacerbate or misrepresent the underlying problems in the transmission system, potentially leading to a P1825 code.

10. What tools are needed to diagnose the P1825 code?

Tools needed may include a diagnostic scan tool, a multimeter for electrical testing, and possibly an oscilloscope to check for detailed signal integrity in the transmission's electronic system.