AutoCodes – GMC – P183D GMC

P183D GMC Code - Internal Mode Switch 2 D2 Circuit High Voltage

Quick Answer

The automatic transmission manual shift shaft position switch assembly, also called the internal mode switch assembly, contains two sliding hall-effect switch assemblies attached to the control valve body within the transmission. Common causes include Faulty Manual Shift Shaft Position Switch Assembly, Manual Shift Shaft Position Switch Assembly harness is open or shorted, Manual Shift Shaft Position Switch Assembly 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: P183D GMC indicates Internal Mode Switch 2 D2 Circuit High Voltage.
Common causes: Common causes include Faulty Manual Shift Shaft Position Switch Assembly, Manual Shift Shaft Position Switch Assembly harness is open or shorted, Manual Shift Shaft Position Switch Assembly 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 864

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 Jan 30, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P183D GMC Description

The automatic transmission manual shift shaft position switch assembly, also called the internal mode switch assembly, contains two sliding hall-effect switch assemblies attached to the control valve body within the transmission. The 9 outputs from the switches indicate which position is selected by the transmission manual shaft. Four outputs (A, B, C, P) are range selection inputs to the transmission control module (TCM). Five outputs (R1, R2, D1, D2, S) are direction selection inputs to the hybrid powertrain control module. The Range input signals are represented as TCM scan tool parameters, Internal Mode Switch A, B, C, and P. The Direction input signals are represented as hybrid powertrain control module scan tool parameters, Internal Mode Switch 2 - R1, R2, D1, D2, and S. The input voltage at the modules is high when a switch is open and low when a switch is closed to earth. Each control module independently supplies power and earth to its respective switch assembly.
The hybrid powertrain control module is internal to the power inverter module, often referred to as the drive motor generator power inverter module and is not serviced separately.

OBDII Code P183D GMC - Internal Mode Switch 2 D2 Circuit High Voltage - AutoCodes.com — P183D GMC Code - Internal Mode Switch 2 D2 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P183D GMC?

Faulty Manual Shift Shaft Position Switch Assembly
Manual Shift Shaft Position Switch Assembly harness is open or shorted
Manual Shift Shaft Position Switch Assembly circuit poor electrical connection

How to Fix the DTC P183D 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 P183D 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.

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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 P183D GMC Code

What does the OBDII code P183D mean on a GMC vehicle?

The P183D code indicates an issue with the Internal Mode Switch (IMS) 2 D2 Circuit, specifically detecting a high voltage condition.

What are the common symptoms of the P183D code?

Common symptoms include erratic shifting, the transmission stuck in one gear, the check engine light illuminated, and reduced vehicle performance.

What causes the P183D code to appear?

Possible causes include a faulty internal mode switch, damaged wiring or connectors in the D2 circuit, short circuits, or a malfunctioning transmission control module (TCM).

How can I diagnose the P183D code?

Start by using a scan tool to confirm the code, inspect the IMS wiring and connectors for damage, check for high resistance or shorts, and test the internal mode switch for proper function.

Can driving with the P183D code cause further damage?

Yes, ignoring this code may lead to transmission performance issues, increased wear, and potential damage to internal components.

How is the P183D code repaired?

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

Is the P183D code specific to GMC vehicles?

While it is commonly associated with GMC vehicles, similar codes and issues may occur in other brands using comparable transmission systems.

What tools are needed to fix the P183D code?

Youâ€™ll need an OBDII scan tool, a multimeter for electrical testing, and possibly specialty tools for accessing the transmission components.

Can a dirty or low transmission fluid level cause the P183D code?

No, this code is specifically related to the electrical circuit of the internal mode switch and is not directly caused by fluid issues, though transmission maintenance is still important.

How much does it cost to fix the P183D code?

Repair costs can range from $150 to $600 or more, depending on whether the issue is wiring-related or if the internal mode switch or TCM requires replacement.