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 DVOM, measure resistance between ground and FCM connector on IPM terminals No. 8 and 43. See Fig 1 . If resistance is 10 ohms or less at each terminal, go to next step. If resistance is greater than 10 ohms at either terminal, repair open in suspect ground circuit. See GROUND DISTRIBUTION article in WIRING DIAGRAMS.
- 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 STANDALONE 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. 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.