LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 1999 >> Forward Control 7.4 J >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Component Tests >> Miscellaneous Controls >> Transmission >> Torque Converter Lock-Up Signal From PCM/VCM
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Torque Converter Lock-Up Signal From PCM/VCM

  1. Warm engine to operating temperature. Raise vehicle and support drive wheels. Support suspension where necessary to prevent damage to drive axles.
  2. Connect a test light to battery voltage. Touch TCC control driver terminal with test light. Accelerate vehicle to 45 MPH and note test light. If test light does not illuminate, problem is a faulty PCM/VCM connector or PCM/VCM.