[Previous][Next]
DTC P0AFA: Hybrid battery voltage low
 
 
danger
  • When servicing the high voltage system parts, always shut off the high voltage by removing the service plug (Refer to ).
  • When servicing the high voltage system parts, always wear the protective equipment or armor to measure the high voltage (Refer to ).
cautionIf there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
 
 
MONITOR EXECUTION
Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • EV-CAN monitor
  • Main drive lithium-ion battery voltage sense circuit monitor
  • Battery-CAN monitor
  • Front electric motor control unit (FEMCU) inverter voltage monitor
  • Rear electric motor control unit (REMCU) inverter voltage monitor
  • Generator control unit (GCU) inverter voltage monitor
Sensor (The sensor below is determined to be normal)
  • Front electric motor control unit (FEMCU) inverter voltage sensor
  • Rear electric motor control unit (REMCU) inverter voltage sensor
  • Generator control unit (GCU) inverter voltage sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
Check Conditions
  • When the vehicle is in the charging mode
Judgment Criterion
  • When a state with the voltage of each condenser (built in the FEMCU, GCU and REMCU) being 178 volts or less continues for 0.2 seconds while the main drive lithium-ion battery is being charged
  • When a state with the voltage of the main drive lithium-ion battery being 184 volts or less continues for 0.2 seconds while the main drive lithium-ion battery is being charged
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 8 .
 
 
PROBABLE CAUSES
  • The high-voltage circuit fails.
  • Blown high-voltage fuse.
  • Main contactor energization circuit fails.
  • Malfunction of the power drive unit (FEMCU).
  • Malfunction of the main contactor.
 
 
DIAGNOSIS
Required Special Tools
  • MB991223: Wiring harness set
  • MB992006: Extra fine probe
STEP 1. Using scan tool (M.U.T.-IIISE), check whether the other DTC is set.
Check if DTC P0C78 is set in the PHEV-ECU.
Is the DTC set?
Carry out troubleshooting for DTC P0C78 (Refer to ). Then go to Step 8.
Go to Step 2.
 
STEP 2. Check the wiring harness for open circuit (PHEV-ECU connector and the main drive lithium-ion battery connector)
Check the wiring harness between PHEV-ECU connector (terminal CNT+) and the main drive lithium-ion battery connector (terminal No.6).
Is the check result normal?
Go to Step 3.
Repair the harness or connector. Then go to Step 8.
 
STEP 3. Check the wiring harness for damage between D-33 main drive lithium-ion battery connector (terminal No.4) and the body ground.
Is the check result normal?
Go to Step 4.
Repair the harness or connector. Then go to Step 8.
 
STEP 4. Check the main drive lithium-ion battery main contactor (P) and (N) <On-vehicles check>.
Check resistance of main contactor (P) and (N) coil with harness connector (Refer to GROUP 54Dc - On-vehicles Service, Check on Coil Resistance of Contactor ).
Is the check result normal?
Go to Step 5.
Replace the main drive lithium-ion battery main contactor (P) or (N) (Refer to GROUP 54Dc - Main Drive Lithium-ion Battery Disassembly and Assembly, Rear JB Assembly, Rear JB Bus Bars (A, B, C, D, M, N, P and T), Contactor and Fuse Removal and Installation ). Then go to Step 8.
 
STEP 5. Check the high-voltage fuse.
danger
  • Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle.
  • Wear the specified protection equipment during the check.
Check the high-voltage fuse (Refer to ).
Is the check result normal?
Go to Step 6.
Engage the high-voltage fuse securely, or replace it (Refer to ). Then go to Step 8.
 
STEP 6. Check the high-voltage circuit.
danger
  • Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle.
  • Wear the specified protection equipment during the check.
Check whether the high-voltage wiring harness is connect securely or damaged.
Is the check result normal?
Go to Step 7.
Reconnect the high-voltage wiring harness. Then go to Step 8.
 
STEP 7. Check the high-voltage circuit.
danger
  • Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle.
  • Wear the specified protection equipment during the check.
(1) Remove the service plug (Refer to ).
(2) Apply a voltage of 12 volts to the CNT- terminal to turn on the charging contactor.
(3) Connect a high-voltage compatible multimeter between the main drive lithium-ion battery high-voltage terminal (REMCU) and the main drive lithium-ion battery service plug rear terminal.
OK: Approximately 100 - 164 volts

(4) Apply a voltage of 12 volts to the CNTP terminal to turn on the charging contactor.
(5) Connect a high-voltage compatible multimeter between the main drive lithium-ion battery high-voltage terminal (REMCU) and the main drive lithium-ion battery service plug front terminal.
OK: Approximately 100 - 164 volts

(6) Apply a voltage of 12 volts to the CNT+ terminal to turn on the charging contactor.
(7) Connect a high-voltage compatible multimeter between the main drive lithium-ion battery high-voltage terminal (REMCU) and the main drive lithium-ion battery service plug front terminal.
OK: Approximately 100 - 164 volts
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Reconnect the high-voltage wiring harness or replace the main drive lithium-ion battery (Refer to GROUP 54Dc - Main Drive Lithium-ion Battery Removal and Installation ). Then go to Step 8.
 
STEP 8. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 8 .
(2) Check the DTC.
Is DTC set?
Retry the troubleshooting.
The inspection is complete.