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Home >> Isuzu >> 2003 >> Rodeo LSE, 3.2 W >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 3.2L >> Diagnostic Tests >> DTC P1640: Output Driver Module No. 1 Circuit Fault >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Check fuse for driver circuit that was shown as faulty. If fuse is blown, go to next step. If fuse is not blown, go to step  4 .
  3. Check for short to ground in suspect driver circuits between ODM drivers and fuses. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  4. Turn ignition off. Disconnect ECM 80-pin harness connectors E-21 (Blue) and E-22 (Red). ECM is located at left rear of engine compartment, near air filter housing. Check for damaged pins, terminals or ECM harness connectors. If problem is found, go to next step. If no problem is found, leave ECM harness connector disconnected and go to step  6 .
  5. Repair damaged pins, terminals or ECM harness connectors. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  6. Using scan tool, select LIGHTS TEST  under MISCELLANEOUS TESTS. Check if light circuit for CHECK ENGINE or CHECK TRANS is indicated as faulty. If light circuit for CHECK ENGINE or CHECK TRANS is indicated as faulty, go to next step. If no problem with circuits are indicated, go to step  13 .
  7. Ensure ECM harness connectors are disconnected. Turn ignition on. Using DVOM, measure voltage between ground and suspect MIL light driver circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If battery voltage is present, go to step  15 . If battery voltage is not present, go to next step.
  8. Turn ignition on. Using DVOM check for battery voltage at C-11 METER fuse. C-11 METER fuse is located in dash fuse box. If battery voltage exists, go to step  10 . If battery voltage does not exist, go to next step.
  9. Repair open in Yellow wire between fuse C-11 and ignition switch. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  10. Turn ignition off. Disconnect ECM 80-pin harness connectors E-21 (Blue) and E-22 (Red). ECM is located at left rear of engine compartment, near air filter housing. Using DVOM, measure resistance between ground and suspect driver terminal in ECM harness connector. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If continuity exists in driver circuit, go to next step. If no continuity exists in driver circuit, go to step  12 .
  11. Repair short to ground between suspect component and driver in ECM. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  12. Repair open circuit between suspect component and driver in ECM. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  13. Connect any disconnected ECM harness connectors. Start engine, and allow to idle. Backprobing measure voltage between ground and suspect driver terminal in ECM harness connector. If battery voltage exists, go to step  15 . If battery voltage does not exist, leave engine idling and go to next step.
  14. Measure voltage at fuse for suspect driver circuit. If battery voltage exists, repeat test beginning in step  10 . If battery voltage does not exist, repeat test beginning in step  9 .
  15. Replace and reprogram ECM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. Use scan tool to clear DTC and verify repair.
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