LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1990 >> Taurus SHO >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Keyless Entry System >> Testing >> Test A, Automatic Locking System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test A, Automatic Locking System

Perform test only instructed by QUICK TEST to do so. This test checks driver's seat switch, courtesy light and switches, back-up light switch, keyless entry module, door ajar switch and related circuits.

  1. Using an ohmmeter, check continuity between pin No. 2 of Brown connector and ground. If continuity exists, go to step 2). If not, repair circuit No. 57 to keyless entry module. See KEYLESS ENTRY MODULE CONNECTOR TERMINAL IDENTIFICATION.
  2. Turn ignition off. Disconnect Brown connector from keyless entry module. With driver's seat unoccupied, check continuity between pins No. 2 and 9 of connector. If no continuity exists, go to step 4). If continuity exists, go to next step.
  3. Disconnect driver's seat switch. Check for short between pin No. 9 of Brown connector and ground. If short is found, repair circuit No. 177 and repeat QUICK TEST. If no short is found, replace driver's seat switch and repeat QUICK TEST.
  4. Have an assistant sit in driver's seat. Check continuity between pins No. 2 and 9 of Brown connector. If continuity exists, go to step 6). If not, go to step 5).
  5. With driver's seat occupied, check continuity between pin No. 9 of Brown connector and driver's seat switch connector, circuit No. 177. If continuity exists, replace seat switch and repeat QUICK TEST. If no continuity exists, repair circuit No. 177 and repeat QUICK TEST.
  6. Using a voltmeter, check voltage between pins No. 2 and 13 of Brown connector. If reading is 10 volts or more, go to next step. If reading is less than 10 volts, check for open or shorts in circuit No. 54. See Figure . Repeat QUICK TEST.
  7. Check that dome/courtesy lights come on when each courtesy light switch is operated. If lights come on, go to step 8). If not, repair switch or wiring and repeat QUICK TEST.
  8. Disconnect Gray connector from module. With all doors closed, check voltage between pin No. 12 of Gray connector and ground. If reading is zero volts, go to step 9). If reading is more than zero volts, repair short to battery voltage or replace door switch that is shorted to battery voltage. Repeat QUICK TEST.
  9. Close all doors. Open any door and check voltage at pin No. 12 of Gray connector. Repeat procedure for every other door. If all readings are 10 volts or more, go to step 10). If not, repair circuit No. 53. Repeat QUICK TEST.
  10. Turn ignition off. Check voltage between pin No. 8 of Brown connector and ground. If reading is zero volts, go to step 11). If reading is more than zero volts, repair or replace ignition switch. Repeat QUICK TEST.
  11. Turn ignition on. Check voltage between pin No. 8 of Brown connector and ground. If reading is 10 volts or more, go to step 13). If reading is less than 10 volts, go to step 12).
  12. Turn ignition off. Check for short between pin No. 8 of Brown connector and ground. Check for continuity between pin No. 8 of Brown connector and circuit No. 194 of ignition switch. If continuity exists and no short to ground, go to step 13). If there is a short to ground or an open circuit, repair circuit No. 194 or check ignition switch. Repeat QUICK TEST.
  13. Turn ignition on. With transmission in Reverse, check voltage between pin No. 10 of Brown connector and ground. Check voltage with transmission in all other positions. If reading is 10 volts in Reverse and zero volts in any other position, replace keyless entry module. If reading is less than 10 volts in reverse or more than zero volts in all other positions, go to step 14).
  14. Test operation of back-up light switch by placing transmission in Reverse. Make sure back-up lights come on. If switch is okay, check for open or short in circuit No. 140. If switch is defective, replace switch and repeat QUICK TEST.
  15. Check resistance between pin No. 14 of Brown connector and ground. Lift outside door handle to open door latch, observe ohmmeter and then close latch with screwdriver. If reading is greater than 10,000 ohms with latch closed and less than 10 ohms with latch open, replace keyless entry module and repeat QUICK TEST.
  16. If reading is less than 10,000 ohms with latch closed, check and/or service door ajar switch circuit. If reading is greater than 10 ohms with latch open, repeat QUICK TEST.
Fig 1: Keyless Entry Module Connector Terminal Identification
G90E14476
scientia non olet · About LEMON Manuals