Bus +/- Signals Open Or No Response From Memory Seat/Mirror Module
NOTE:
After making any repairs, perform MEMORY SYSTEM VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition on. Using DVOM, select BODY then BODY COMPUTER. If scan tool identifies and/or communicates with Body Control Module (BCM), go to next step. If scan tool does not identify and/or communicate with BCM, go to BUS +/- SIGNALS OPEN OR NO RESPONSE FROM BCM .
- Turn ignition off. Locate and disconnect Memory Seat/Mirror Module (MSMM) connectors. See COMPONENT LOCATIONS . Using a test light connected to ground, probe MSMM connector C1 terminal No. 2 (Orange/Red wire). See Fig 2 and Fig 3 . If test light illuminates, go to next step. If test light does not illuminate, repair open or short to ground in Orange/Red wire between MSMM and power seat circuit breaker located under driver's seat or between power seat circuit breaker and fuse No. 22 (40-amp) located in Intelligent Power Module (IPM). See Fig 1.
- Turn the ignition off. Disconnect the memory seat/Mirror module C4 harness connector. See Fig 2 and Fig 3 . Using a 12 volt test light connected to 12 volts, probe the ground circuits. If the test light illuminated, go to the next step. If the test light did not illuminate, repair the ground circuit for an open.
- Turn the ignition off. Disconnect the memory seat/Mirror module C1 harness connector. See Fig 2 and Fig 3 . Obtain Scope Input Cable (CH7058), Cable To Probe Adapter (CH7062) and Red and Black test probes. Connect scope input cable to channel 1 connector on scan tool. Connect Red and Black test probes and probe adapter to scope input cable. Select PEP MODULE TOOLS on scan tool. Select LAB SCOPE then LIVE DATA. Select 12V SQUARE WAVE. Press F2 for scope then enter to select channel. Press F2 again and use down arrow to set voltage range to 20 volts. Set probe to x10. Press F2 again to complete. Connect Black probe to ground and Red probe MSMM connector C2 terminal No. 26 (White/Violet wire). Turn ignition on. Monitor scope on scan tool. If voltage pulses between zero and 7.5 volts, go to next step. If voltage does not pulse between zero and 7.5 volts, repair open in White/Violet wire (PCI bus circuit) between MSMM and diagnostic junction port terminal No. 11. See Figure.
- Replace MSMM. See MEMORY SEAT/MIRROR MODULE under REMOVAL & INSTALLATION.