LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Diagnosis - A/T >> Service Bulletins >> Checking For Ground At Terminal "D" At Transmission

Checking For Ground At Terminal "D" At Transmission

  1. Check for ground at terminal "D" at transmission. See WIRING DIAGRAMS . On non-computer controlled vehicles, see COOLER LINE PRESSURE TEST. On all other vehicles, raise and support vehicle (if necessary). Disconnect transmission electrical connector and connect test light ground wire to terminal "A" of transmission connector. Install tip of test light into terminal "D" of transmission connector.
  2. Start engine and run to normal operating temperature. Place gear selector in Drive (O.D. on 4 speed transmissions). Accelerate slowly to 60 MPH. Test light should light. If test light does not light, computer system problem exists. Shave insulation off of wire "D", or pierce wire near transmission connector.
  3. Connect one end of jumper wire to wire "D" at shaved or pierced area. Ground other end of jumper wire. With vehicle on lift, road test for lock-up. If unsure lock-up occurred, hold steady speed of 60 MPH and slightly touch and release brake pedal. Disengagement and re-engagement should be felt. Seal bare wire connection with silicon after test is complete (if necessary).
scientia non olet · About LEMON Manuals