DTC P0A1B-788: Drive Motor "A" Control Module: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Check if DTCs are output.

   Result

   DTC No.	Relevant Diagnosis
   U0110-160, 159, 656, 657	Lost Communication with Drive Motor Control Module

   HINT: 

   • Turning the power switch on (IG) with the service plug grip and inverter cover removed causes interlock switch system DTC P0A0D-350 to be output.
   • P0A1B-788 may be output due to a malfunction which causes the DTCs in the table above to be output. In this case, first troubleshoot the output DTCs in the table above. Then, perform a reproduction test to check that no DTCs are output.

YES → See step   8 

NO: Go to next step 

NG → CONNECT SECURELY 

OK: Go to next step 

1. Turn the power switch off and remove the service plug grip. Refer to PRECAUTION .
   NOTE:

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

2. Remove the IGCT relay from the engine room R/B.
3. Disconnect the A62 inverter with converter assembly connector.
4. Measure the resistance according to the value(s) in the table below.
   Fig 1: Identifying Connector Terminal Identification (Inverter With Converter Assembly - Engine Room R/B)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   +B (A62-31) - IGCT relay terminal 5	Below 1 Ω
   +B2 (A62-30) - IGCT relay terminal 5	Below 1 Ω
   GND1 (A62-11) - Body ground	Below 1 Ω
   GND2 (A62-10) - Body ground	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   +B (A62-31) or +B2 (A62-30) - Body ground	10 kΩ or more

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Check that the service plug grip is not installed.
2. Check that the bolts for the motor cable are tightened to the specified torque.
   Fig 2: Identifying Motor Cable Bolt Location

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   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 N*m (82 kgf*cm, 71 in.*lbf) 

NG → TIGHTEN TO SPECIFIED TORQUE 

OK: Go to next step 

1. Check that the service plug grip is not installed.
2. Check that the bolts for the generator cable are tightened to the specified torque.
   Fig 3: Identifying Motor Cable Bolt Location

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   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 N*m (82 kgf*cm, 71 in.*lbf) 

NG → TIGHTEN TO SPECIFIED TORQUE 

OK: Go to next step 

1. Check that the service plug grip is not installed.
2. Disconnect the generator cable and motor cable from the inverter with converter assembly. Refer to REMOVAL .
3. Using a milliohmmeter, measure the resistance according to the value(s) in the table below. (Check MG1 for an interphase short.)
   Fig 4: Identifying Generator Cable And Motor Cable Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT: 

   If the MG1 temperature is high, the resistance varies greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

   Standard resistance

   Tester Connection	Specified Condition
   U - V	59 to 65 mΩ
   V - W	56 to 62 mΩ
   W - U	56 to 62 mΩ

   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 (68°F) (mΩ)
     • Rt: Measured resistance (mΩ)
     • T: Temperature when the resistance is measured (°C)
4. Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.
   NOTE:

   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

   Tester Connection	Specified Condition
   U - Body ground and shielded wire ground	100 MΩ or more
   V - Body ground and shielded wire ground	100 MΩ or more
   W - Body ground and shielded wire ground	100 MΩ or more

NG → See step   9 

OK: Go to next step 

1. Check that the service plug grip is not installed.
2. Disconnect the generator cable and motor cable from the inverter with converter assembly. Refer to REMOVAL .
3. Using a milliohmmeter, measure the resistance according to the value(s) in the table below. (Check MG2 for an interphase short.)
   Fig 5: Identifying Generator Cable And Motor Cable Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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

   Tester Connection	Specified Condition
   U - V	69.5 to 76.5 mΩ
   V - W	66.5 to 73.5 mΩ
   W - U	66.5 to 73.5 mΩ

   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 (68°F) (mΩ)
     • Rt: Measured resistance (mΩ)
     • T: Temperature when the resistance is measured (°C)
4. Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.
   NOTE:

   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

   Tester Connection	Specified Condition
   U - Body ground and shielded wire ground	100 MΩ or more
   V - Body ground and shielded wire ground	100 MΩ or more
   W - Body ground and shielded wire ground	100 MΩ or more

NG → See step   9 

OK → See step   10