AutoCodes – Buick – B1440 Buick

B1440 Buick Code - Power Mode Master Input Circuits Mismatch

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: B1440 Buick indicates Power Mode Master Input Circuits Mismatch.
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 1,817

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 17, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1440 Buick Description

The vehicle Power Mode Master (PMM) is the Body Control Module (BCM). The ignition switch is a low current switch with multiple discrete ignition switch signals to the PMM for determination of the power mode. The PMM receives the ignition switch signals, and additionally a reference voltage signal from the BCM, through the ignition switch, and back to the BCM. There are redundancies within the PMM system that can allow operation of certain subsystems when there are faults in the ignition switch circuits. Other information such as serial data input from other modules and DTCs is also used to determine what power mode signals and information is transmitted by the PMM. The BCM logic uses all this information 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 PMM serial data message does not match what the individual module can detect from its own connections.
The PMM will activate relays and other direct outputs of the PMM 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 short to ground, the B+ circuit fuse to the ignition switch will open.

OBDII Code B1440 Buick - Power Mode Master Input Circuits Mismatch - AutoCodes.com — B1440 Buick Code - Power Mode Master Input Circuits Mismatch

What does this mean?

What are the Possible Causes of the DTC B1440 Buick?

Faulty Ignition Switch
Ignition Switch harness is open or shorted
Ignition Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1440 Buick?

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 B1440 Buick 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 B1440 Buick Code

What are the common symptoms of OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch?

Symptoms may include issues with starting the vehicle, loss of power steering, illumination of warning lights on the dashboard, and possible engine stalling.

What are the possible causes of OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch?

Potential causes may include faulty wiring or connections in the power mode master input circuits, a malfunctioning power mode master switch, or issues with the power mode master control module.

How can I diagnose OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch?

Diagnosis typically involves using a diagnostic scanner to retrieve the specific trouble code, inspecting the wiring and connections in the power mode master input circuits, testing the power mode master switch, and checking the power mode master control module for proper operation.

What are some repair tips for addressing OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch?

Repair tips may include repairing or replacing any damaged wiring or connections, replacing a faulty power mode master switch, or reprogramming or replacing the power mode master control module as needed.

Is it safe to continue driving my Buick with OBDII code B1440 related to Power Mode Master Input Circuits Mismatch?

It is not recommended to continue driving the vehicle with this code present, as it can lead to potential safety hazards and further damage to the vehicle's systems. It is best to address the issue promptly.

Can I reset OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch on my own?

While you can attempt to clear the code using a diagnostic scanner, it is important to diagnose and address the underlying issue causing the code to prevent it from recurring.

What is the typical cost to repair OBDII code B1440 in a Buick related to Power Mode Master Input Circuits Mismatch?

The cost of repair can vary depending on the specific cause of the code and the needed repairs. It is advisable to consult a professional mechanic for an accurate diagnosis and cost estimate.

How can I prevent OBDII code B1440 related to Power Mode Master Input Circuits Mismatch in my Buick in the future?

Regular maintenance, such as checking and maintaining the electrical system, can help prevent issues that may trigger this code. Additionally, addressing any warning signs promptly can help prevent more severe problems.