OBD-II FAULT CODE
P1631

Theft Deterrent Start Enable Signal Not Correct/ Main Relay Malfunction (Power Hold)

Reference information for P1631. Because this is manufacturer-specific, confirm the exact definition for the vehicle before using the diagnostic guidance below.

Manufacturer-specific code

This code can have different meanings depending on vehicle make, model and year. Treat the definition below as a reference and confirm it with OEM service information before diagnosis or repair.

PowertrainSystem
General diagnosticCategory
MediumSeverity
  • Check Engine light
  • Poor drivability or reduced fuel economy depending on fault
  • Faulty related sensor/actuator
  • Wiring or connector issue
  • Poor ground/power supply
  • Control module fault is possible but less common
  • Scan all modules and record freeze-frame data before clearing codes
  • Check battery voltage and related fuses
  • Repair wiring/connector/fuse issues first
  • Replace the related sensor/actuator only after testing confirms failure
  • Use OEM service manual for brand-specific procedures
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Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.