P0A78-306 - Drive Motor "A" Inverter Performance

L110 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-306: Drive Motor "A" Inverter Performance
P0A78-306 - Drive Motor "A" Inverter Performance

DESCRIPTION

For a description of the inverter, P0A78.

The MG ECU controls motor torque according to driving conditions.

MONITOR DESCRIPTION

If the difference between the requested MG2 torque and the actual MG2 torque exceeds a predetermined value, the MG ECU determines that there is a malfunction in the execution or monitoring of the MG2 torque. Then, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

INSPECTION PROCEDURE

CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting, check the voltage at the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (HV)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:

HINT
P0A78-306 may be set due to a malfunction which also causes DTCs in the table above to be set. In this case, first troubleshoot the output DTCs in the table above. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

YES -- GO TO DTC CHART
NO -- Continue to next step.

2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

(a) Check the connection of the low voltage connector of the inverter with converter assembly.

Result:

The connector is connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

3. CHECK INVERTER WITH CONVERTER ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

CAUTION:
Be sure to wear insulated gloves.

(a) Turn the power switch off and remove the service plug grip L110 Hybrid Vehicle Control System.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check that the bolts for the motor cable are tightened to the specified torque.

NOTICE:
Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

Torque : 8.0 Nm (82 kgf-cm, 71 in-lbf)

NG -- TIGHTEN TO SPECIFIED TORQUE
OK -- Continue to next step.

4. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MG2)

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

CAUTION:
Be sure to wear insulated gloves.

(b) Disconnect the generator cable and motor cable from the inverter with converter assembly Service and Repair.

(c) Using a milliohmmeter, measure the resistance according to the value(s) in the table below. (Check MG2 for an interphase short.)

HINT
If the MG2 temperature is high, the resistance varies greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

Standard resistance:

HINT
- To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68° F).
* R20 = Rt / {1 + 0.00393 X (T - 20)}
- The calculation is based on the following:
* R20: Resistance at 20°C (mOhms)
* Rt: Measured resistance (mOhms)
* T: Temperature when the resistance is measured (° C)

(d) Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

NOTICE:
Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard resistance:

OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Service and Repair
NG -- Continue to next step.

5. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

(a) Remove the hybrid vehicle transmission assembly Components.

(b) Check that the bolts for the motor cable are tightened to the specified torque.

NOTICE:
Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

Torque : 8.0 Nm (82 kgf-cm, 71 in-lbf)

NG -- TIGHTEN TO SPECIFIED TORQUE
OK -- Continue to next step.

6. CHECK MOTOR CABLE

(a) Remove the motor cable from the transmission Components.

(b) Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

NOTICE:
Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard resistance:

Standard resistance:

NG -- REPLACE MOTOR CABLE

OK -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY Components