AutoCodes – Generic – B1370

B1370 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 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 27,006

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 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 - Control Module Ignition ON and Start Circuit - AutoCodes.com — B1370 Code - Control Module Ignition ON and Start Circuit

What does this mean?

What are the Possible Causes of the DTC B1370?

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?

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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1370 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 code?

Need more information on how to fix the B1370 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1370 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1370 Buick — Control Module Ignition ON and Start Circuit
B1370 Cadillac — Control Module Ignition ON and Start Circuit
B1370 Chevrolet — Control Module Ignition ON and Start Circuit
B1370 Ford — Door Handle Ground Supply Signal Stuck
B1370 GMC — Control Module Ignition ON and Start Circuit
B1370 Hyundai — Front-Passenger Seat Belt Pretensioner Circuit Short To Battery
B1370 KIA — Front-Passenger Seat Belt Pretensioner Circuit Short To Battery
B1370 Lincoln — Door Handle Ground Supply Signal Stuck
B1370 Mercury — Door Handle Ground Supply Signal Stuck

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 Code

1. What are the common symptoms of OBDII code B1370?

- Common symptoms include issues with starting the vehicle, engine stalling, and problems with the ignition system.

2. What could cause the OBDII code B1370 to be triggered?

- The code B1370 is typically triggered by a malfunction in the control module ignition ON and start circuit, which can be caused by a faulty ignition switch, wiring issues, or a defective control module.

3. How can I diagnose the cause of OBDII code B1370?

- To diagnose the cause of code B1370, you can perform a visual inspection of the ignition system components, check for loose or damaged wiring, and use a diagnostic scanner to analyze the control module data.

4. What are the repair options for fixing OBDII code B1370?

- Repair options for OBDII code B1370 may include replacing the faulty ignition switch, repairing damaged wiring, or replacing the control module if necessary.

5. Can I still drive my vehicle with OBDII code B1370 present?

- It is not recommended to drive your vehicle with OBDII code B1370 present, as it can cause potential safety hazards and lead to further damage to the ignition system.

6. How much does it typically cost to repair OBDII code B1370?

- The cost of repairing OBDII code B1370 can vary depending on the underlying cause of the issue, but it may range from $100 to $500 for parts and labor.

7. Is it possible to reset OBDII code B1370 without repairing the issue?

- While you can clear the code temporarily with an OBDII scanner, it is important to address the root cause of the problem to prevent it from recurring.

8. Can extreme weather conditions trigger OBDII code B1370?

- Yes, extreme weather conditions such as extreme cold or heat can sometimes exacerbate existing issues in the control module ignition ON and start circuit, leading to the triggering of code B1370.

9. How long does it typically take to repair OBDII code B1370?

- The repair time for OBDII code B1370 can vary depending on the complexity of the issue and the availability of parts, but it may take anywhere from a few hours to a full day to complete the repair.

10. Are there any preventive measures to avoid OBDII code B1370 in the future?

- To prevent OBDII code B1370 in the future, it is recommended to perform regular maintenance checks on the ignition system, including inspecting wiring and components for any signs of wear or damage.