AutoCodes – GMC – P1915 GMC

P1915 GMC Code - Internal Mode Switch Start/Wrong Range

Quick Answer

The park/neutral position switch and the 5 Hall Effect switches are internal to and part of the internal mode switch assembly. Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission 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: P1915 GMC indicates Internal Mode Switch Start/Wrong Range.
Common causes: Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission 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 5,658

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 Mar 23, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1915 GMC Description

The park/neutral position switch and the 5 Hall Effect switches are internal to and part of the internal mode switch assembly. The park/neutral switch indicates to the engine control module (ECM) if the vehicle is in park/neutral or in a drive gear range. With the ignition ON, the ECM provides 12 V on the park/neutral signal to the park/neutral position switch. A separate ground wire from the park/neutral position switch to the Transmission Control Module (TCM) completes the path to ground. When the gear shift lever in park or neutral, the switch closes and drops the voltage on the signal circuit to 0 V. In this state the engine will start and run. In reverse or drive range the park/neutral switch opens, 12 V is then present on the signal circuit which will inhibit engine starting. The Diagnostic Trouble Code (DTC) will be set when the internal mode switch Park/Neutral circuit does indicate Park or Neutral during engine start.

OBDII Code P1915 GMC - Internal Mode Switch Start/Wrong Range - AutoCodes.com — P1915 GMC Code - Internal Mode Switch Start/Wrong Range

What does this mean?

What are the Possible Causes of the DTC P1915 GMC?

Faulty Transmission Internal Mode Switch
Transmission Internal Mode Switch harness is open or shorted
Transmission Internal Mode Switch circuit poor electrical connection
Faulty Transmission Control Module (TCM)

How to Fix the DTC P1915 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 P1915 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 P1915 GMC code?

Need more information on how to fix the P1915 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1915 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P1915 2014 GMC Sierra — Internal Mode Switch Start/Wrong Range
P1915 2015 GMC Sierra — Internal Mode Switch Start/Wrong Range
P1915 2016 GMC Sierra — Internal Mode Switch Start/Wrong Range
P1915 2017 GMC Sierra — Internal Mode Switch Start/Wrong Range
P1915 2018 GMC Sierra — Internal Mode Switch Start/Wrong Range

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 P1915 GMC Code

1. What are the common symptoms of OBDII code P1915 GMC?

The common symptoms of code P1915 GMC include issues with starting the vehicle, incorrect gear indication on the dashboard, and potential stalling or rough idling.

2. What causes the OBDII code P1915 GMC to trigger?

The code P1915 GMC is typically triggered by a malfunction in the internal mode switch, which is responsible for determining the position of the gear selector.

3. How serious is the OBDII code P1915 GMC?

While the code itself may not lead to immediate safety concerns, it can cause inconvenience and potential drivability issues if left unresolved. It is recommended to address the issue promptly.

4. Can driving with the OBDII code P1915 GMC cause further damage?

Continuing to drive with the P1915 code may lead to erratic shifting, stalling, or potential transmission damage. It is advisable to address the underlying problem as soon as possible.

5. How can I diagnose the OBDII code P1915 GMC?

Diagnosing the P1915 code involves using a scan tool to read the code, inspecting the internal mode switch for any visible damage, and testing the switch's functionality.

6. Is it possible to repair the OBDII code P1915 GMC at home?

Depending on your mechanical skills and access to tools, it may be possible to repair the code P1915 GMC at home by replacing the internal mode switch yourself.

7. What are some tips for repairing the OBDII code P1915 GMC?

When repairing the P1915 code, make sure to use a high-quality replacement internal mode switch, follow manufacturer guidelines for installation, and clear the code after the repair.

8. Can a faulty internal mode switch be cleaned or repaired instead of replaced?

In some cases, a faulty internal mode switch may be cleaned to remove debris or corrosion causing the issue. However, if the switch is damaged or worn out, replacement is recommended.

9. How much does it typically cost to repair the OBDII code P1915 GMC at a repair shop?

The cost of repairing the P1915 code at a repair shop can vary depending on labor rates and the price of the internal mode switch. It is advisable to obtain quotes from different shops.

10. Is it safe to continue driving with the OBDII code P1915 GMC if the vehicle is still running normally?

While the vehicle may still run normally with the P1915 code present, it is not recommended to ignore the issue. Addressing the problem promptly can prevent further complications and potential safety hazards.