Toyota Corolla Cross: Motor/Generator Shutdown Signal Stuck Off (P321E9F)

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU detects malfunctions which prevent the inverter with converter assembly emergency shutdown circuit (HSDN) from shutting down the hybrid control system. Detection is performed when the ignition switch is turned to ON and during the shutdown sequence when the ignition switch is turned off.

The cause of this malfunction may be one of the following:

• Hybrid vehicle control ECU malfunction
• Connector or wire harness malfunction (between hybrid vehicle control ECU and inverter with converter assembly) malfunction
• Inverter with converter assembly malfunction

DESCRIPTION

The hybrid vehicle control ECU sends a block signal to the motor generator control ECU (MG ECU) to shut down the power supply to the motor. When the system is not in the on (READY) state, it sends an HSDN (MG shutdown signal) signal from the hybrid vehicle control ECU to the motor generator control ECU (MG ECU) to check the function of the HV gate block. When a malfunction is detected in the HV gate block function, DTCs are stored.

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

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1. Connect the GTS to the DLC3.
2. Turn the ignition switch to ON and turn the GTS on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
4. Turn the ignition switch off and wait for 2 minutes or more.
5. Turn the ignition switch to ON (READY) and wait for 30 seconds or more.
6. Turn the ignition switch off and wait for 2 minutes or more.
7. Turn the ignition switch to ON (READY) and wait for 30 seconds or more.
8. Turn the ignition switch off and wait for 2 minutes or more.
9. Turn the ignition switch to ON and turn the GTS on.
10. Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
11. Check the DTC judgment result.

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE, perform driving pattern again.

WIRING DIAGRAM

Refer to the wiring diagram for the Shut Down Signal Circuit.

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CAUTION / NOTICE / HINT

CAUTION:

Refer to the precautions before inspecting high voltage circuit.

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NOTICE:

• After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.

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• When disconnecting and reconnecting the auxiliary battery

  HINT:

  When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

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HINT:

• P321E9F may be output as a result of the malfunction indicated by the DTCs in table below.
  1. The chart above is listed in inspection order of priority.
  2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)

PROCEDURE

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NG

CONNECT SECURELY

OK

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B

CONNECT SECURELY

C

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the inverter with converter assembly connector.

(c) Disconnect the hybrid vehicle control ECU connector.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

HINT:

As there might be an intermittent malfunction, inspect the following items even if the measured resistance is as specified.

Check that each connector between the inverter with converter assembly and hybrid vehicle control ECU is not loose or disconnected.

(e) Reconnect the hybrid vehicle control ECU connector.

(f) Reconnect the inverter with converter assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the inverter with converter assembly connector.

(c) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A187-26 (HSDN) - A187-4 (GND1) Ignition switch off 2.65 to 3.55 kΩ NOTICE: Be sure not to damage or deform the terminal being inspected.

*a Component without harness connected (Inverter with Converter Assembly)

(d) Reconnect the inverter with converter assembly connector.

OK

REPLACE HYBRID VEHICLE CONTROL ECU

NG

REPLACE INVERTER WITH CONVERTER ASSEMBLY

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