Cellular Communications System Diagnosis

Wiring Schematic:

CIRCUIT DESCRIPTION
The battery voltage is supplied to the cellular telephone module at module connector terminal A. The cellular telephone module uses this power feed in order to perform all of the module's functions.

CONDITIONS FOR SETTING THE DTC
The battery voltage measured at terminal A is more than 15.5 V for four monitoring cycles.

ACTION TAKEN WHEN THE DTC SETS
When DTC B1982 is current, Class 2 loss of serial data DTCs are not set.

CONDITIONS FOR CLEARING THE DTC
The battery voltage is less than 15.5 V in the next monitoring cycle.

DIAGNOSTIC AIDS
Use a scan tool in order to monitor the cellular telephone module battery voltage display.
^ If the voltage displayed is 15.5 V or less and DTC B1982 is current, replace the cellular telephone module.
^ If the voltage displayed is 15.5 V or more, refer to Charging System Diagnosis.