B1447
DTC B1447
Circuit Description
The vehicle communication interface module (VCIM) detects the Back-up Battery (BUB) is no longer connected to the VCIM.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1447 Back-up Power Source
Conditions for Running the DTC
* The ignition must be in the RUN or ACC position.
* The system voltage is at least 9.5 volts and no more than 15.5 volts.
* All the above conditions are present for greater than 10 seconds
Conditions for Setting the DTC
The VCIM detects no voltage from the back-up battery
Action Taken When the DTC Sets
* The VCIM will be unable to place a call in the event of a main battery disconnect during a collision event.
* The OnStar(R) status LED turns RED.
Conditions for Clearing the MIL/DTC
* The VCIM detects voltage from the back-up battery.
* A history DTC clears after 50 malfunction-free ignition cycles.
* The VCIM receives the clear DTC command from the scan tool.
Diagnostic Aids
DTC B1447 may set if the VCIM has been incorrectly disconnected or services. When disconnecting the VCIM, disconnect the harness connector C1 at the VCIM prior to disconnecting any other harness connectors. This will ensure the BUB is preserved when voltage is removed from the VCIM.
Test
