P0637 OBD II Trouble Code Power Steering Control Circuit High

How to quickly diagnose and repair, and causes of a P0637 electrical code which indicates a high electrical situation within the power steering control circuit.

Symptoms of P0637 OBD II Trouble Code

  • Stiff or erratic steering
  • Noise while turning
  • Check engine light illuminated

Common Causes of P0637 OBD II Trouble Code

  • Defective power steering pressure switch
  • Defective power steering position switch
  • Faulty power steering control
  • A loose control module ground strap or broken ground wire
  • Insufficient fluid level or leak
  • Blown fuse or fuse-able link (if applicable)
  • Corroded or damaged connector
  • Faulty or damaged wiring
  • Defective PCM

Severity of P0637 OBD II Trouble Code

The severity of this code can vary tremendously from just an illuminated check engine light on a vehicle that operates normally to a stiff or erratic steering issue. Steering problems can become a safety issue when not given immediate attention.