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Description & Operation: Notes

WARNING: Deactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEMS article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

The multiplex control system is controlled and monitored by the body No. 1 and the body No. 2 Electronic Control Units (ECUs). See Fig 1. Other components in the system include the following:

If equipped, system may also include the following:

A bus cut relay is located inside body No. 1 ECU and body No. 2 ECU. If communication bus is shorted, bus cut relay will disconnect affected portion of circuit. If no switch input change is received for 30 seconds, ECU interrupts communication to save battery power.

Fig 1: Identifying Multiplex Communications Components
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