What does P1632 mean on a Chevy?

P1632. Theft Deterrent Fuel Disable Signal Received. Applies to Silverado, Sierra, Tahoe, Impala, Corvette.

What causes P1632 on a Chevy?

BCM actively disabling fuel after a failed theft deterrent authentication Faulty key transponder or Passkey III key not recognized Failed theft deterrent exciter at the ignition cylinder Aftermarket alarm system triggering the factory immobilizer

How do I fix P1632 on a Chevy?

Try a known-good factory key to rule out transponder failure Check for aftermarket alarm or remote-start splices interfering with the VTD circuit Perform the Passlock/Passkey relearn procedure per service information Scan the BCM for theft deterrent codes with a Tech2/GDS2 scan tool and diagnose those first

Code

P1632

Theft Deterrent Fuel Disable Signal Received

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Silverado, Sierra, Tahoe, Impala, Corvette
Related: No single generic twin. See OBD Codes List

What it means

P1632. Theft Deterrent Fuel Disable Signal Received. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Impala, Corvette.

Findings, check these first

BCM actively disabling fuel after a failed theft deterrent authentication
Faulty key transponder or Passkey III key not recognized
Failed theft deterrent exciter at the ignition cylinder
Aftermarket alarm system triggering the factory immobilizer

Standard procedure

Try a known-good factory key to rule out transponder failure
Check for aftermarket alarm or remote-start splices interfering with the VTD circuit
Perform the Passlock/Passkey relearn procedure per service information
Scan the BCM for theft deterrent codes with a Tech2/GDS2 scan tool and diagnose those first

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 2026-09-13.

Report a correction for P1632. Include your vehicle, the issue and a source if you have one.

This fault sits in the GM theft deterrent system. The GM security codes and Passlock relearn guide covers the families and the relearn cycles.