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Home >> Suzuki >> 2001 >> Esteem GL, 4D Sedan, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - Esteem 1.6L >> Diagnostic Tests >> DTC P1600: Serial Communication Problem Between ECM & TCM >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Perform DTC CONFIRMATION TEST  . If DTC P01600 is set, go to next step. If DTC P1600 is not set, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
  2. Turn ignition on. Measure voltage (backprobe) between ground and ECM 22-pin connector E92 terminal No. 5 (Green/Yellow wire). See Figure . If reading is about 5 volts, go to step  5 . If reading is not about 5 volts, go to next step. If reading toggles between zero and 5 volts, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
  3. Turn ignition off. Disconnect TCM connector. Turn ignition on. Measure voltage between ground and TCM 28-pin harness connector E25 terminal No. 27 (Green/Yellow wire). If reading is about 5 volts, check for an open in TCM power or ground circuits. Repair as necessary. If circuits are okay, replace TCM and go to DTC CONFIRMATION TEST  . If reading is not about 5 volts, check for short to ground in Green/Yellow wire between ECM and TCM. See WIRING DIAGRAMS article. Go to next step.
  4. If wire is okay, disconnect ECM 22-pin connector E92. Check for poor terminal contact at ECM 22-pin connector E92. If poor terminal contact is found, repair as necessary and go to DTC CONFIRMATION TEST  . If terminal contact is okay, replace ECM and go to DTC CONFIRMATION TEST  .
  5. Check for open in Green/Yellow wire between ECM and TCM. Check for an open in TCM power or ground circuits. Repair as necessary. If circuits are okay, replace TCM and go to DTC CONFIRMATION TEST  .
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