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Home >> Suzuki >> 1999 >> Swift Automatic >> Repair and Diagnosis >> Restraints >> Air Bag, SRS >> Air Bag Restraint System >> Diagnostic Tests >> SDM Cannot Communicate Through Serial Data Circuit >> Diagnostic Procedure
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Diagnostic Procedure

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK  .
  2. Before continuing with diagnosis, ensure scan tool is operating properly and correct cartridge is installed. Turn ignition off. Ensure scan tool is connected properly to DLC. If connection is okay, go to next step. If connection is not okay, repair as necessary and go to step 9).
  3. Disconnect driver and passenger-side air bag connector at behind steering wheel side cap and behind glove box. See Figure . Disconnect SDM connector. See Figure . Measure resistance between DLC terminal No. 9 and SDM connector terminal No. 1. See Figure . If resistance is less than infinite, go to next step. If resistance is infinite, an open in Violet/Red or Violet wire. Replace wiring harness. Go to step 9).
  4. If vehicle is not equipped with ABS, go to next step. If vehicle is equipped with ABS, attempt to establish communication with ABS control module using scan tool. If communication is not okay, go to next step. If communication is okay, recheck connection with DLC. If connection is okay, replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION  . Go to step 9).
  5. Turn ignition off. Disconnect ABS control module (if equipped). Measure resistance between DLC terminals No. 4 and 9. If resistance is infinite, go to next step. If resistance is less than infinite, a short to ground exists in Violet/Red or Violet wire between DLC and SDM connectors. Replace wiring harness. Go to step 9).
  6. Turn ignition on. Measure voltage between DLC terminals No. 4 and 9. If voltage is one volt or less, go to next step. If voltage is more than one volt, a short to voltage exists in Violet/Red or Violet wire. Replace wiring harness. Go to step 9).
  7. If vehicle is not equipped with ABS, go to next step. If vehicle is equipped with ABS, turn ignition off. Reconnect driver and passenger-side air bag connectors. Reconnect SDM. Ensure ABS control module is disconnected. Attempt to establish communication with SDM using scan tool. If communication is not okay, go to next step. If communication is okay, a short to ground or voltage exists in ABS control module. Replace ABS control module. Go to step 9).
  8. Turn ignition off. Ensure connectors at SDM and DLC are secure. If connectors are secure, replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION  . Go to next step.
  9. Reconnect all SIR system components. Using scan tool, clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK  .
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