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DTC U1064: Lost Communications With Body Control Module

  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 U1064. If scan tool displays LAST TEST FAILED for DTC U1064, go to next step. If scan tool does not display LAST TEST FAILED for DTC U1064, problem is intermittent. Check for any poor connections to Body Control Module (BCM). See COMPONENT LOCATIONS  and WIRING DIAGRAMS  . Repair as necessary and retest operation.
  3. Turn ignition off. Gain access to Body Control Module (BCM), located under upper instrument panel trim panel, behind instrument cluster. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Disconnect BCM. Connect test light between ground and Light Blue 24-pin BCM connector terminals No. A11 and B10 (Orange wires). See Figure. If test light illuminates, go to step  5. If test light does not illuminate, go to next step.
  4. Repair open in appropriate Orange wire between BCM and instrument panel fuse block. See WIRING DIAGRAMS . Repair as necessary and retest operation. If Orange wires check okay, go to next step.
  5. Connect test light between ground and Brown 24-pin BCM connector terminal A12 (Pink wire). See Figure. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, repair open in Pink wire between Brown 24-pin BCM connector terminal A12 and IGN 1 fuse (10-amp), located in instrument panel fuse block. Retest operation.
  6. Connect test light between ground and Light Blue 24-pin BCM connector terminal A3 (Yellow wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Yellow wire between Light Blue 24-pin BCM connector terminal A3 and RADIO (IGN) fuse (10-amp), located in instrument panel fuse block. Retest operation.
  7. Connect test light between battery voltage and Light Blue 24-pin BCM connector terminals B1 and B11 (Black wires). If test light illuminates, go to next step. If test light does not illuminate, repair open in appropriate Black wire between BCM and ground. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.
  8. Connect test light between battery voltage and Brown 24-pin BCM connector terminal B2 (Black wire). If test light illuminates, go to next step. If test light does not illuminate, repair open in Black wire between BCM and ground. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.
  9. Check for poor connections to BCM. Repair as necessary. If BCM connections are okay, replace BCM. See BODY CONTROL MODULE (BCM)  under REMOVAL & INSTALLATION. Retest operation.
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