2000 Saturn SC2 Automatic, MP6FACTORY OEM SERVICE PROCEDURE

DTC U1088: Lost Communications With Sensing And Diagnostic Module (SDM)

  1. Perform VEHICLE ON-BOARD DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. If body control module diagnostic system check has been performed, go to next step.
  2. Observe scan tool display for DTC U1088. If scan tool displays LAST TEST FAILED for DTC U1088, go to next step. If scan tool does not display LAST TEST FAILED for DTC U1088, problem is intermittent. Check for any poor connections to Sensing and Diagnostic Module (SDM). See COMPONENT LOCATIONS . See appropriate AIR BAG RESTRAINT SYSTEMS article. Repair as necessary and retest operation.
  3. Disconnect Sensing and Diagnostic Module (SDM), located under rear of center console. Connect test light between ground and Yellow 18-pin SDM connector terminal No. 1 (Yellow wire). See Fig 1. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between SDM and AIR BAG fuse (10-amp), located in instrument panel fuse block. See appropriate AIR BAG RESTRAINT SYSTEMS article.
  4. Connect test light between battery voltage and Yellow 18-pin SDM connector terminal No. 16 (Black wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Black wire between SDM and ground. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.
  5. Check for poor connections to SDM. Repair as necessary. If SDM connections are okay, replace SDM. See appropriate AIR BAG RESTRAINT SYSTEMS article. Retest operation.
Fig 1: Identifying Sensing & Diagnostic Module (SDM) Connector Terminals
G00012168Courtesy of GENERAL MOTORS CORP.
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