[Previous][Next]
DTC P0AA8: Leak Sensor Detection Circuit Open
 
 
 
 
DESCRIPTIONS OF MONITOR METHODS
  • The monitor executes immediately after hybrid system launch.
  • Precheck circuit can simulate isolation state intentionally when "Precheck signal status is on".
  • The monitor judges circuit malfunction when the monitor cannot detect the isolation state at "Precheck signal status is on".
  • The monitor detects a malfunction by using "Isolation counter 1".
 
 
MONITOR EXECUTION
  • Once per driving cycle
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • BMU (SUB) power supply voltage is 8 volts to 16 volts.
  • Time after above conditions satisfy is more than 3.5 seconds.
  • Precheck signal status is on.
Judgment Criterion
  • Isolation counter 1 is less than 2 times for 25.4 seconds.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to OBD-II Drive Cycle - Pattern 1 .
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Not available
 
 
PROBABLE CAUSES
  • Ground fault of high voltage system component.
  • The main drive lithium-ion battery ground fault detector failed.
  • Open circuits of main drive lithium-ion battery ground fault detector circuit, short circuits to ground, short circuits to power supply system or damage; poor contact of connector.
  • The sub-battery management unit [BMU (SUB)] is failed.
 
 
 
DIAGNOSIS
Required Special Tools
  • MB991658: Test harness
dangerWhen high voltage system components are serviced, be sure to pull service plugs to shut down high voltage before servicing (Refer to ).
dangerWhen pulling service plugs, wear the specified protective equipment (Refer to ).
STEP 1. Measure the resistance at main drive lithium-ion battery connector.
(1) Disconnect the D-34 main drive lithium-ion battery connector, and measure at the wiring harness side.
(2) Check the resistance between the D-34 main drive lithium-ion battery connector (terminal No.6) and body ground.
OK: Continuity exist (2 Ω or less)
Is the check result normal?
Go to Step 2.
Repair the connector(s) or wiring harness. Then go to Step 3.
 
STEP 2. Check of open circuit in line between main drive lithium-ion battery connector and sub-battery management unit [BMU (SUB)] connector.
(1) Remove the battery tray cover (Refer to ).
(2) Disconnect the sub-battery management unit [BMU (SUB)] connector, and measure at the wiring harness side.
(3) Check the resistance between the sub-battery management unit [BMU (SUB)] connector (LGND terminal) and D-34 main drive lithium-ion battery connector (terminal No.6).
OK: Continuity exists (2 Ω or less)
(4) Check the resistance between the sub-battery management unit [BMU (SUB)] connector (TP1 terminal) and sub-battery management unit [BMU (SUB)] connector (TP2 terminal). <High voltage>
OK: Continuity exists (2 Ω or less)
Is the check result normal
Replace the sub-battery management unit [BMU (SUB)] (Refer to ). Then, assemble the main drive lithium-ion battery assembly (Refer to ). Then go to Step 3.
Repair the connector(s) or wiring harness. Then, assemble the main drive lithium-ion battery assembly (Refer to ). Then go to Step 3.
 
STEP 3. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to OBD-II Drive Cycle - Pattern 1 .
(2) Check the DTC set.
Is the DTC set?
Retry the troubleshooting.
The inspection is complete.