If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, always diagnose the CAN bus lines.
OPERATION
If the IGBT (inverter) temperature is expected to exceed the specified temperature in the driving mode, the MCU shut off the IGBT (inverter) circuit in order to protect the internal circuit.
DIAGNOSIS CODE SET CONDITIONS
If the estimated IGBT (inverter) temperature is 125°C or more in the driving mode, the MCU will set the diagnosis code No. P1B17.
note
The diagnosis code may be set during a high-load driving around 0 km/h (the maximum torque for 20 seconds or longer on driving off on a steep road or stopping with tyre locked).
PROBABLE CAUSES
High-load driving around 0 km/h (the maximum torque for 20 seconds or longer on driving off on a steep road or stopping with tyre locked) was performed.
Malfunction of the MCU
Malfunction of the EV-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnosis
Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting .) Then go to Step 2.
STEP 2. Diagnosis code recheck
Check again if the diagnosis code No. P1B17 is set to the MCU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Go to Step 3.
The diagnosis is complete.
STEP 3. M.U.T.-III Diagnosis code of other systems
Check if the diagnosis code is set to the EV-ECU.
Q.
Is the diagnosis code set?
Carry out troubleshooting for the EV-ECU. (Refer to .) Then go to Step 4.
Go to Step 4.
STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the MCU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the MCU. (Refer to .) Then go to Step 5.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
STEP 5. Diagnosis code recheck
Check again if the diagnosis code is set to the MCU.
(1)Erase the stored diagnosis code.
(2)Set the electric motor switch from the LOCK (OFF) position to the ON position.
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting 
.) Then go to Step 2.