P0A1B-788 - Drive Motor "A" Control Module

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0A1B-788: Drive Motor "A" Control Module
P0A1B-788 - Drive Motor "A" Control Module

DESCRIPTION

If the inverter with converter assembly (MG ECU) is reset due to a problem with the power source in the inverter, the hybrid vehicle control ECU will set this DTC.

HINT
The term "drive motor A" indicates MG2.

MONITOR DESCRIPTION

If an abnormal power source IC CPU reset is detected in the MG ECU, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

WIRING DIAGRAM

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 for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
NOTICE:
If the problem still occurs after clearing the DTCs using the Techstream when DTC U0110-159, 160, 656 or 657 is detected, DTC P0A1B-788 will be stored. However, it is not necessary to perform inspection for DTC P0A1B-788 because DTC P0A1B-788 indicates a communication system malfunction.

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) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:

(e) Turn the power switch off.

B -- GO TO DTC CHART Hybrid Control System
A -- Continue to next step.

2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR) P0343

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

3. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - ENGINE ROOM J/B)

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Turn the power switch off.

(c) Disconnect the low voltage connector A59 from the inverter with converter assembly.

(d) Remove the IGCT relay from the engine room junction block assembly.

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

Text in Illustration

Standard Resistance (Check for open):

Standard Resistance (Check for short):

NOTICE:
Do not apply excessive force when using the probes of the tester to perform the inspection. If excessive force is used, the terminals will be damaged.

(f) Install the IGCT relay.

(g) Connect the inverter with converter assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK INVERTER WITH CONVERTER ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check that the bolts for the generator cable are tightened to the specified torque, the generator cable is connected securely, and there are no contact problems.

Specified Condition:

T=8.0 N*m {82 kgf*cm, 71 in.*lbf}

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).

(c) Check for arc marks at the terminals for the generator cable.

Result:

C -- CONNECT SECURELY

B -- REPLACE MALFUNCTIONING PARTS
A -- Continue to next step.

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

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check that the bolts for the generator cable are tightened to the specified torque, the motor cable is connected securely, and there are no contact problems.

C -- CONNECT SECURELY

B -- REPLACE MALFUNCTIONING PARTS
OK -- Continue to next step.

6. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG1)

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the generator (MG1) cable and motor (MG2) cable from the inverter with converter assembly.

(c) Check MG1 for an interphase short using a milliohmmeter.

(1) Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

HINT
If the MG1 temperature is high, the resistance will vary greatly from the specification. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

Standard Resistance:

Text in Illustration

HINT
To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 68° F (20°C).

- R20 = Rt / {1 + 0.00393 X (T - 20)}
The calculation is based on the following:

- R20: Resistance at 68° F (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:

(e) Connect the generator cable and motor cable.

NG -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Components
OK -- Continue to next step.

7. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2)

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 power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the generator (MG1) cable and motor (MG2) cable from the inverter with converter assembly.

(c) Check MG2 for an interphase short using a milliohmmeter.

(1) Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

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

Standard Resistance:

Text in Illustration

(e) Connect the generator cable and motor cable.

NG -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Components

OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components