CUSTOMER CONCERN The vehicle stalled while driving, required towing, and had a depleted high-voltage battery with DTCs P261A13, C1259, and C1A50. CAUSE The confirmed repair identified a failed 12-volt auxiliary battery as the cause of the stall and related hybrid-system faults. CORRECTION Remove and replace the failed 12-volt auxiliary battery, clear DTCs P261A13, C1259, and C1A50, and verify Ready mode, charging, and normal vehicle operation.

CUSTOMER CONCERN A 12-volt battery warning appears, the vehicle will not drive, and DTC P300000 is stored for hybrid battery discharge control. CAUSE The confirmed repair identified a failed 12-volt auxiliary battery. CORRECTION Remove and replace the failed 12-volt auxiliary battery, clear DTC P300000, and verify the vehicle enters Ready mode and drives normally.

CUSTOMER CONCERN The vehicle intermittently will not power up; the instrument cluster remains dark but the vehicle starts normally with a jump. CAUSE The 12-volt auxiliary battery failed under load and could not support vehicle startup. CORRECTION Remove and replace the failed 12-volt auxiliary battery and verify the hybrid system powers up normally without a jump start.

CUSTOMER CONCERN The 12-volt auxiliary system reads 0 volts at the jump-start terminals. The vehicle starts with a jump but returns to 0 volts after the charger is disconnected. CAUSE Low auxiliary-battery voltage caused the Battery Management System to open the B+ relay, isolating the auxiliary battery from the vehicle. CORRECTION Press the auxiliary-battery reset switch, jump-start the vehicle, allow the hybrid system to recharge the auxiliary battery, and verify the vehicl

CUSTOMER CONCERN The 12-volt battery is not charging and the DC/DC converter module stores DTC U3000:04. CAUSE The 12-volt battery failed and could not accept or maintain the converter's charging output. CORRECTION Remove and replace the failed 12-volt battery, clear DTC U3000:04, and verify the DC/DC converter charges the low-voltage system normally.

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 auxiliary battery repeatedly requires a jump start. DTCs C2300 and C2318 are stored, and battery voltage measures approximately 10 volts. CAUSE Parasitic draw measured only 36 milliamps, confirming the discharged auxiliary battery itself could not retain normal voltage. CORRECTION Remove and replace 12-volt auxiliary battery. Clear DTCs C2300 and C2318 and verify normal battery voltage and vehicle power-up.

CUSTOMER CONCERN Customer states the vehicle will not crank or start and nearly all electrical systems are inoperative after the 12-volt battery went dead. CAUSE Voltage testing found no power at the engine-compartment battery terminal, confirming the 120-amp DC/DC fusible link was open. CORRECTION Remove and replace 120-amp DC/DC fusible link. Inspect remaining power-distribution fuses and verify normal vehicle power-up and READY-mode operation.

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 brake actuator makes a loud clunk or bang with the brake pedal applied. DTC C1241 is stored. CAUSE C1241 subcode testing confirmed the 12-volt battery was failing and causing low system voltage. CORRECTION Remove and replace 12-volt battery. Clear brake-system DTCs and verify normal brake-actuator operation.

CUSTOMER CONCERN Customer states the 12-volt battery goes dead overnight or after the vehicle sits for several days. DTC B1318 may be stored. CAUSE Battery load testing confirmed the 12-volt battery could not maintain the required voltage. CORRECTION Remove and replace 12-volt battery. Clear low-voltage DTCs and verify normal starting operation.