OBD Guide

P1631

Theft Deterrent Start Enable Signal Not Correct

Severity
🔴 High
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Engine won't start
  • The engine stalls immediately after starting
  • The anti-theft system indicator is flashing
  • Check Engine light comes on
  • Problems with the ignition system

Causes

  • Malfunction of the anti-theft system module
  • Problems with the ignition key or transponder
  • Open or short circuit in the anti-theft system circuit
  • Engine control unit (ECU) malfunction
  • Problems with communication between modules

How to Fix

  1. Check the condition of the ignition key and transponder
  2. Diagnose the anti-theft system module
  3. Check the integrity of wiring and connections
  4. Read fault codes of all modules
  5. Reprogram or replace the anti-theft system module if necessary

Related codes

Error P1631 by Vehicle Brand