DESCRIPTION
The cause of this malfunction may be the FC air compressor motor high-voltage circuit.
Check the FC air compressor motor internal resistance and the connection condition of the high-voltage line between the inverter and FC air compressor motor to check whether there is an open or short circuit.
| Area | Inspection | Step |
|---|---|---|
| FC air compressor motor cable connection check | Check for the connection condition of the cable from the inverter to the FC air compressor motor. | 1 |
| FC air compressor motor or FC air compressor motor cable | Check the FC air compressor motor (including cable) internal resistance and the insulation resistance with body ground to check for an open or short circuit. | 2 |
WIRING DIAGRAM
| *a | FC Air Compressor with Motor Assembly |
| *b | Inverter with Converter Assembly |
| *c | High Voltage Line |
CAUTION / NOTICE / HINT
This step is referenced from the procedures for each DTC.
If the inspection results below are normal, perform the next procedure for the referenced DTC.
CAUTION:
Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grips from both FC stack assembly and EV battery.
Inspecting the high-voltage system
Disconnecting the low voltage connector of the inverter with converter assembly
Disconnecting the low voltage connector of the EV battery
Disconnecting the low voltage connector of the FC stack assembly
Disconnecting the low voltage connector of the FC converter assembly
Tech Tips
No removal order is specified for the service plug grips of the FC stack assembly and EV battery.
After removing the service plug grip from the EV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system. After removing the service grip from the FC stack assembly, store it in a safe location and use the "HIGH-VOLTAGE, DO NOT TOUCH" sign to notify other technicians that you are working on the high-voltage system.
| *a | Without waiting for 10 minutes |
After removal of the service plug grips of both FC stack assembly and EV battery, wait for at least 10 minutes before touching the high-voltage connectors and 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.
Tech Tips
At least 10 minutes are necessary to discharge the high-voltage capacitors inside the inverter with converter assembly and FC stack assembly.
Note
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
When reinstalling the service plug grip to the FC stack assembly or the EV battery, slide the lever of the service plug until the letters "UNLOCK" are completely hidden, and insert it firmly.
When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work (If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).
PROCEDURE
CHECK INVERTER WITH CONVERTER ASSEMBLY (FC AIR COMPRESSOR MOTOR CABLE CONNECTION CONDITION)
CAUTION:
Be sure to wear insulated gloves.
Check that the service plug grip is not installed to FC stack assembly and EV battery.
Note
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.
Remove the inverter terminal cover from the inverter with converter assembly.
Tech Tips
Make sure that no foreign matter, coolant or water has entered the inverter assembly with converter. Confirm that the inverter coolant volume has not increased.
| *1 | FC Air Compressor Motor Cable |
Check that the bolts for the FC air compressor motor cable are tightened to the specified torque, the FC air compressor motor cable is connected securely, and there are no contact problems.
| Specified Condition |
|---|
| T = 8.0 N*m (82 kgf*cm, 71 in.*lbf) |
Note
Make sure that the tightening torque of the bolt is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).
Disconnect the FC air compressor motor cable from the inverter with converter assembly.
Check for arc marks at the terminals for the FC air compressor motor cable.
| Result | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||||||
Connect the FC air compressor motor cable to the inverter with converter assembly.
Install the inverter terminal cover.
| B |
|
REPLACE MALFUNCTIONING PARTS |
| C |
|
CONNECT SECURELY |
| A |
|
CHECK FC AIR COMPRESSOR WITH MOTOR ASSEMBLY
CAUTION:
Be sure to wear insulated gloves.
Check that the service plug grip is not installed to FC stack assembly and EV battery.
Note
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.
Remove the inverter terminal cover from the inverter with converter assembly.
Tech Tips
Make sure that no foreign matter, coolant or water has entered the inverter assembly with converter. Confirm that the inverter coolant volume has not increased.
| *1 | FC Air Compressor Motor Cable |
Disconnect the FC air compressor motor cable from the inverter with converter assembly.
| *1 | FC Air Compressor Motor Cable (Inverter with Converter Assembly Side) |
| *2 | Shield Ground |
Check the FC air compressor motor for an interphase short using a milliohmmeter.
Using a milliohmmeter, measure the resistance according to the value(s) in the table below.
Tech Tips
If the FC air compressor motor 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 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
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 (°F).)
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 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the FC air compressor motor cable.
Install the inverter terminal cover.
| Result | |||
|---|---|---|---|
|
| OK |
|
FC AIR COMPRESSOR HIGH-VOLTAGE CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC) |
| NG |
|
REPLACE FC AIR COMPRESSOR WITH MOTOR ASSEMBLY Click here |