What does B1440 mean on a Chevy?

B1440. Power Mode Master Input Circuit Mismatch. Applies to Silverado, Sierra, Tahoe, Suburban, Avalanche.

What causes B1440 on a Chevy?

Faulty ignition switch sending incorrect power mode signal Body control module (BCM) power mode input mismatch Chafed ignition feed wiring in the steering column harness Aftermarket remote start or alarm tapped into ignition feeds Weak battery causing module wake-up disagreement

How do I fix B1440 on a Chevy?

Compare power mode PIDs between the BCM and other modules Inspect the ignition switch connector for heat damage Look for aftermarket remote start or alarm wiring taps Test ignition switch feed circuits for correct voltage in each key position Replace the ignition switch if its outputs disagree with key position

Code

B1440

Power Mode Master Input Circuit Mismatch

Category: Body
Severity: Body Warning Light
Applies to: Silverado, Sierra, Tahoe, Suburban, Avalanche
Related: No single generic twin. See OBD Codes List

What it means

B1440. Power Mode Master Input Circuit Mismatch. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Suburban, Avalanche.

Findings, check these first

Faulty ignition switch sending incorrect power mode signal
Body control module (BCM) power mode input mismatch
Chafed ignition feed wiring in the steering column harness
Aftermarket remote start or alarm tapped into ignition feeds
Weak battery causing module wake-up disagreement

Standard procedure

Compare power mode PIDs between the BCM and other modules
Inspect the ignition switch connector for heat damage
Look for aftermarket remote start or alarm wiring taps
Test ignition switch feed circuits for correct voltage in each key position
Replace the ignition switch if its outputs disagree with key position

Look up another code

Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.

Sources and review

Review: no source links are recorded for this entry.

Last updated 2026-09-25.

Report a correction for B1440. Include your vehicle, the issue and a source if you have one.