No Response From Front Control Module
NOTE:
After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition on. Using scan tool, attempt to communicate with Occupant Restraint Controller (ORC), Controller Anti-Lock Brake (CAB) and Body Control Module (BCM). If scan tool identifies or communicates with any module, go to next step. If scan tool does not identify or communicate with any module, go to PCI BUS COMMUNICATION FAILURE .
- Turn ignition off. Remove Front Control Module (FCM) from Intelligent Power Module (IPM). See COMPONENT LOCATIONS . Using a 12-volt test light connected to 12 volts, probe ground and FCM connector on IPM terminals No. 8 and 43. See Fig 1. If the test light illuminated for each circuit, go to next step. If the test light did not illuminate for each circuit, repair open in suspect ground circuit. See GROUND DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- 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 the probe to x10. Press F2 again to complete. Connect Black probe to ground and Red probe to FCM connector terminal No. 22. 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 FCM and diagnostic junction port terminal No. 9. See Figure.
- Replace FCM. See FRONT CONTROL MODULE under REMOVAL & INSTALLATION.