B1009

B1009 - EEPROM Checksum Mismatch

CIRCUIT DESCRIPTION
Battery voltage is supplied to the OnStar Communication Interface Module (CIM) by circuit 1640. This input is internally monitory by the CIM for proper operating voltage. The minimum voltage for proper operation is 9.0 volts, if circuit 1640 drops below 9.0 volts, this DTC will fail. DTC B1327 will remain current until system voltage is above 9.5 volts for 1.2 seconds. Under 8.5 volts, communication with OnStar system using scan tool will be disabled.

DTC PARAMETERS
^ Voltage on circuit 1640 is between 8.5 - 9.0 volts for 1.2 seconds
^ Illuminate the red OnStar LED.

DIAGNOSTIC AIDS
^ Check for poor connections at the CIM and instrument panel fuse block. Inspect harness for backed out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals and poor terminal-to-wire connections (terminal crimped over insulation).
^ If fault is suspected to be intermittent, moving harness wiring may help in locating fault.

TEST DESCRIPTION

Diagnostic Chart: