Trouble Shooting
Trouble Shooting the Tesla Board
Below are procedures for trouble shooting common errors with the Tesla board. More information can be found on the small and large drive unit support threads of the forum. If you have an issue and find/get a solution, please add to this page.
Persistent overcurrent error
1) Powerup with only 12v. No hv. Is the error there? if yes then change the sign of the parameter ocurlim. Some versions of firmware require this to be negative. Newer versions it must be positive. When testing I flip this sign to simulate an error and sometimes forget to flip it back before saving parameters.
2)If the error is present when only 12v is applied regardless of ocurlim parameter polarity then one of 2 things are at fault. The logic board or the inverter. To determine which is the problem requires some diagnostic testing of the signals coming from the current sensors to the logic board and the value of voltage at 2 test points on the logic board.These test points may be found in the bottom right hand side of the board adjacent to R45 and R58. Using a multimeter on DC volts measure the voltage between each test point and 12v ground. At idle (no hv no throttle no run signals) a voltage of approx 1.65v should be present here.
3) If the error occurs when starting the inverter , then remove hv , set udcsw to 0 and try to start with no hv. If the error occurs then most likely cause is a faulty inverter power section.
4)if the error occurs only with hv present then disconnect the inverter from the motor and try again. If the error is still present then most likely cause is a faulty inverter power section.
The motor is only turning slowly when I press the throttle
The symptom of the motor turning slowly is almost certainly caused by a missing or inverted encoder signal. The encoder output consists of two channels : A and B. The signal from these is used by the microcontroller to determine the speed and direction of rotation of the motor. If for example the A and B signals are swapped then the inverter will be trying to drive the motor in one direction and the encoder signal will tell it the motor is running backwards hence this behavior. If either or both signals are missing then the microcontroller has no speed or direction information and the same symptoms result.
In some versions of the LDU the encoder wiring is swapped. If the motor will only turn slowly, try swapping the two encoder wires.
The motor turns but is not smooth
If you ever have issues getting a stable spinning motor, Always plot your rpm/Fstat as if that is really jumpy it means the encoder signal is dirty.
Shielded cable is a must, without it the encoder pulses are not clean enough. Use either the factory harness or cat5e/cat6 shielded cable. The shield is connected on the 23-pin ampseal connector but not connected on the encoder plug.
My motor was spinning when high voltage was cut by a contactor opening or fuse. Now it won't run.
The back EMF from the spinning motor fried the inverter. A replacement inverter or full drive unit replacement is needed.