CUSTOMER CONCERN The 12-volt battery discharges while driving and the vehicle shuts down when system voltage falls to 10.9 volts. CAUSE Voltage testing found 15.0 volts at the DC/DC converter output stud but only 12.1 volts at the E202 terminal and battery because corrosion at the exposed output-stud connection created excessive resistance. CORRECTION Disassemble and clean the corroded DC/DC converter output-stud terminal connection, reassemble the circuit, and verify approxi

CUSTOMER CONCERN Customer states the 12-volt battery is not charging. DTCs P0A08-264, P0AE6 and P2519 are stored, and battery voltage falls from 12.53 volts with the vehicle in READY mode. CAUSE DC/DC converter power and ground testing confirmed the converter was not producing charging voltage for the auxiliary battery. CORRECTION Remove and replace DC/DC converter. Clear DTCs and verify stable 12-volt charging voltage in READY mode.

CUSTOMER CONCERN Customer states the battery warning light is on and the 12-volt charging system is inoperative. DTC P0A94 is stored. CAUSE Battery cables between the DC-DC converter and 12-volt battery were clean and tight, confirming an internal DC-DC converter failure. CORRECTION Remove and replace DC-DC converter. Clear DTC P0A94 and verify 12-volt charging operation.

CUSTOMER CONCERN Customer states the 12-volt charging system is inoperative after high-voltage battery replacement and DTC P0A94 is stored. CAUSE Fuse 3 and the power supply at terminal 2 of the DC-DC converter four-pin black connector tested correctly, confirming an internal DC-DC converter fault. CORRECTION Remove and replace DC-DC converter. Clear DTC P0A94 and verify 12-volt charging operation.

CUSTOMER CONCERN The 12-volt battery was not charging even though scan data showed the DC-DC converter commanded on and a 13.9-volt target. CAUSE The DC-DC converter failed to produce charging voltage. CORRECTION The DC-DC converter was replaced.