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DTC U1040: EBTCM Class 2 Source Id 28: Testing

  1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK  .
  2. Turn ignition switch to LOCK position. Disconnect scan tool. Disconnect splice pack SP205. See COMPONENT LOCATIONS  . Using DVOM, individually check resistance between SP205 terminal "A" and each terminal "B", "E", "G", "L", and "M". See Figure . If resistance is less than 2 ohms at all terminals, go to next step. If resistance is not less than 2 ohms at all terminals, go to step 7).
  3. Disconnect EBTCM Light Gray 24-pin connector C1. See COMPONENT LOCATIONS  . Using DVOM, check resistance between SP205 harness connector terminal "E" (Light Blue wire) and ground. If resistance is infinite, go to next step. If resistance is not infinite, go to step 8).
  4. Turn ignition switch to RUN position. Using DVOM, check voltage between SP205 harness connector terminal "E" (Light Blue wire) and ground. If reading is less than 2 volts, go to next step. If reading is not less than 2 volts, go to step 9).
  5. Using DVOM, check resistance between SP205 harness connector terminal "E" (Light Blue wire) and EBTCM harness connector C1, terminal A1 (Light Blue wire). If resistance is less than 2 ohms, go to next step. If resistance is not less than 2 ohms, go to step 10).
  6. Turn ignition switch to LOCK position. Reconnect EBTCM connector C1. Connect scan tool. Turn ignition switch to RUN position. Using scan tool, attempt to establish communication with EBTCM. If scan tool communicates with EBTCM, go to step 11). If scan tool does not communicate with EBTCM, go to ANTI-LOCK BRAKES article in BRAKES section.
  7. Replace splice pack SP205. Go to step 11).
  8. Repair short to ground in Light Blue wire between EBTCM connector C1 and splice pack SP205. Go to step 11).
  9. Repair short to battery in Light Blue wire between EBTCM connector C1 and splice pack SP205. Go to step 11).
  10. Repair poor connection or open in Light Blue wire between EBTCM connector C1 and splice pack SP205. Go to step 11).
  11. Turn ignition switch to LOCK position. Reinstall all components and connectors. Turn ignition switch to RUN position. Using scan tool, clear DTCs. Check for DTCs. If any DTCs are current, perform BCM DIAGNOSTIC SYSTEM CHECK  . If no DTCs are current, system is operating properly.
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