54Da-DTC P0AA1 MAIN CONTACTOR P WELD

DTC P0AA1: Main contactor P weld

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 ).

caution

Before replacing the ECU, ensure that the communication circuit is normal.

DESCRIPTIONS OF MONITOR METHODS

The inverter voltage of the front electric motor control unit (FEMCU) or rear electric motor control unit (REMCU) is monitored to judge ON/OFF status of each contactor.
The stuck on failure of each contactor is judged under the following conditions.

Main contactor (P) stuck ON: Main contactor (P) control circuit active command off.
Main contactor (P) stuck ON: Main contactor (N) control circuit active command on.
Main contactor (P) stuck ON: Charging contactor control circuit active command off.

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
Front electric motor control unit (FEMCU) current monitor
Front electric motor control unit (FEMCU) coil temperature monitor
Front electric motor control unit (FEMCU) IGBT temperature monitor
Front electric motor control unit (FEMCU) capacitor temperature monitor
Front electric motor control unit (FEMCU) control module temperature monitor
Front electric motor control unit (FEMCU) 3 phase circuit monitor
Rear electric motor control unit (REMCU) current monitor
Rear electric motor control unit (REMCU) coil temperature monitor
Rear electric motor control unit (REMCU) IGBT temperature monitor
Rear electric motor control unit (REMCU) capacitor temperature monitor
Rear electric motor control unit (REMCU) control module temperature monitor
Rear electric motor control unit (REMCU) 3 phase circuit monitor
Front electric motor control unit (FEMCU) inverter voltage monitor
Rear electric motor control unit (REMCU) inverter voltage monitor
Front electric motor control unit (FEMCU) Control module circuit monitor
Rear electric motor control unit (REMCU) control module circuit monitor

Sensor (The sensor below is determined to be normal)

Front electric motor control unit (FEMCU) current sensor
Front electric motor control unit (FEMCU) coil temperature sensor
Front electric motor control unit (FEMCU) position sensor
Front electric motor control unit (FEMCU) IGBT temperature sensor
Front electric motor control unit (FEMCU) capacitor temperature sensor
Front electric motor control unit (FEMCU) control module temperature sensor
Rear electric motor control unit (REMCU) current sensor
Rear electric motor control unit (REMCU) coil temperature sensor
Rear electric motor control unit (REMCU) position sensor
Rear electric motor control unit (REMCU) IGBT temperature sensor
Rear electric motor control unit (REMCU) capacitor temperature sensor
Rear electric motor control unit (REMCU) control module temperature sensor
Front electric motor control unit (FEMCU) inverter voltage sensor
Rear electric motor control unit (REMCU) inverter voltage sensor

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

The charging contactor activation command off.
The main contactor (P) activation command off.
The main contactor (N) activation command on.
The front electric motor control unit (FEMCU) or rear electric motor control unit (REMCU) discharge status on.

Judgment Criterion

Change of the front electric motor control unit (FEMCU) voltage is more than 150 volts for 2 seconds.
Change of the rear electric motor control unit (REMCU) voltage is more than 150 volts for 2 seconds.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 4 .

PROBABLE CAUSES

Damaged harness or connector.
Malfunction of charge contactor.^*
Malfunction of main contactor (P) (weld).^*
Malfunction of electric heater.^*
Malfunction of the A/C compressor.^*
Malfunction of the on board charger/DC-DC converter.^*
Malfunction of the FEMCU.^*
Malfunction of the REMCU.^*
Malfunction of the GCU.^*
Malfunction of the AC converter. <Vehicles with AC power supply>^*
Malfunction of the PHEV-ECU.

note	^*: Welding is caused when the high voltage circuit of the high voltage components stays on.

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 P0AE7 is set in the PHEV-ECU.

Is the DTC set?

Carry out troubleshooting for the DTC P0AE7 (Refer to

). Then go to Step 8

Go to Step 2

STEP 2. Check the signal line for short to power supply circuit (PHEV-ECU connector and main drive lithium-ion battery connector).

(1) Disconnect the connector and measure at the harness connector side.

(2) Check the wiring harness between PHEV-ECU connector and the main drive lithium-ion battery connector (terminal CNT+).

Is the check result normal?

Go to Step 3

Repair the connector or wiring harness. Then go to Step 8

STEP 3. Voltage measurement at high-voltage, service plug connector.

danger

Carry out the check on the high-voltage circuit while reading carefully the precautions on handling a high-voltage vehicle.
Be sure to wear the specified protective equipment when removing the service plug.

(1) Remove the service plug (Refer to

(2) 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 0 volt

Is the check result normal?

Go to Step 7

Replace the contactor (Refer to GROUP 54Dc - Main Drive Lithium-ion Battery Disassembly and Assembly, 15. Front JB Assembly, Front JB Bus Bars (D, E, F, N and P), Electric Current Sensor, Contactor and Resistor Removal and Installation

). Then go to Step 4

STEP 4. Using scan tool (M.U.T.-IIISE), check whether the other DTC is set.

Check whether the other DTC, which is associated with the FEMCU, the GCU, the REMCU, the inverter (incorporated in the on-board charger/DC-DC converter), is set in the PHEV-ECU (Refer to

Is any DTC set?

Troubleshoot for the relevant DTC. Then go to Step 8

Go to Step 5

STEP 5. Using scan tool (M.U.T.-IIISE), check whether the other DTC is set.

Check whether DTC is set in the A/C-ECU, A/C compressor assembly and electric heater-ECU (Refer to GROUP 55 - Diagnostic Trouble Code Chart

<A/C-ECU>,

<A/C compressor assembly>,

<electric heater-ECU>).

Is the DTC set?

Troubleshoot for the relevant DTC. Then go to Step 8

Go to Step 6

STEP 6. Check the electric heater ON failure.

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) Disconnect the electric heater connector (high voltage) and measure at the equipment side.

(3) Measure the resistance between electric heater connector (high voltage) (terminal No.1 and No.2).

OK: No continuity (Reference value: 1 MΩ or more)

note	If you mistake the polarity of the tester, you can not measure correctly.

Is the check result normal?

Go to Step 7

Check the high-voltage fuse No.5 (Refer to GROUP 54Db - Check and Replacement of The High-voltage Fuse Inside The Inverter

). Replace the electric heater (Refer to GROUP 55 - Heater

). Then go to Step 8

STEP 7. 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 4

(2) Check the DTC.

Is the DTC set?

Replace the PHEV-ECU (Refer to

). Then go to Step 8

The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction

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 4

(2) Check the DTC.

Is the DTC set?

Retry the troubleshooting.

The procedure is complete.