AutoCodes – GMC – B1370 2015 GMC Sierra

B1370 2015 GMC Sierra Code - Control Module Ignition ON and Start Circuit

Quick Answer

The vehicle Power Mode Master (PMM) is the Body Control Module (BCM). Common causes include Faulty Ignition Switch, Ignition Switch harness is open or shorted, Ignition 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: B1370 2015 GMC Sierra indicates Control Module Ignition ON and Start Circuit.
Common causes: Common causes include Faulty Ignition Switch, Ignition Switch harness is open or shorted, Ignition 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 227

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 Apr 17, 2023

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
FAQs
Comments
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Code B1370 2015 GMC Sierra Description

The vehicle Power Mode Master (PMM) is the Body Control Module (BCM). The ignition switch is a low-current switch with multiple discrete circuits to the BCM. The BCM logic uses the ignition switch positions to identify the operator's desired power mode and activate specific discrete signals, and serial data messages for the operation of different subsystems as necessary. Other modules which have switched voltage inputs may operate in a default mode if the Power Mode Master serial data message does not match what the individual module can detect from its own connections.
The Power Mode Master will activate relays and other direct outputs of the Power Mode Master as needed according to the calculated power mode. Some relays controlled by the BCM are switched ignition voltage outputs that are pass-through circuits within the BCM directly from the ignition switch. If these circuits are short to ground, the B+ circuit fuse to the ignition switch will open.

OBDII Code B1370 2015 GMC Sierra - Control Module Ignition ON and Start Circuit - AutoCodes.com — B1370 2015 GMC Sierra Code - Control Module Ignition ON and Start Circuit

What does this mean?

What are the Possible Causes of the DTC B1370 2015 GMC Sierra?

Faulty Ignition Switch
Ignition Switch harness is open or shorted
Ignition Switch circuit poor electrical connection
Faulty Body Control Module (BCM)
Faulty Instrument Cluster (If code is stored in Instrument Cluster)

How to Fix the DTC B1370 2015 GMC Sierra?

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 does this mean?

Code Tech Notes

B1370:01 Control Module Ignition ON and Start Circuit Short to Battery
B1370:04 Control Module Ignition ON and Start Circuit Short to Ground or Open

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1370 2015 GMC Sierra 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 B1370 2015 GMC Sierra code?

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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 B1370 2015 GMC Sierra Code

1. What does the OBDII code B1370 mean on a 2015 GMC Sierra?

The B1370 code indicates an issue in the Control Module Ignition ON and Start Circuit, often involving a fault in the ignition system wiring or related components.

2. What are the common symptoms of the B1370 code in a 2015 GMC Sierra?

Symptoms may include difficulty starting the vehicle, intermittent starting issues, or the ignition staying on even after turning the key off.

3. What causes the B1370 code in a 2015 GMC Sierra?

Common causes include damaged wiring, a faulty ignition switch, a malfunctioning control module, or corroded electrical connections in the ignition circuit.

4. Can driving with the B1370 code damage my 2015 GMC Sierra?

While it may not cause immediate damage, ignoring the code can lead to more severe electrical issues and increased difficulty starting your vehicle.

5. How do you diagnose the B1370 code in a 2015 GMC Sierra?

A technician will use a diagnostic scanner to confirm the code, inspect the ignition circuit wiring, and check for faulty components like the ignition switch or control module.

6. What repairs are needed to fix the B1370 code on a 2015 GMC Sierra?

Repairs may include replacing damaged wiring, repairing corroded connections, replacing the ignition switch, or reprogramming the control module.

7. Is the B1370 code common in GMC Sierra vehicles?

This code is not extremely common but can occur in GMC Sierras, especially if the ignition system experiences wear or electrical issues.

8. How much does it cost to fix the B1370 code on a 2015 GMC Sierra?

Repair costs vary depending on the issue but typically range from $100 to $500, including parts and labor.

9. Can I reset the B1370 code myself in my 2015 GMC Sierra?

You can clear the code using an OBDII scanner, but it will likely return unless the underlying issue is resolved.

10. Do I need professional help to fix the B1370 code in a 2015 GMC Sierra?

While some issues like inspecting wiring can be done at home, diagnosing and repairing ignition system components usually requires professional expertise.