agreed..can be tough code to troubleshoot, especially without access to manual, training to understand components and their interaction. When the code appears though, can give good clues as to where to look first. If key-on self test code appears, usually looking at "hard" failure ie: TM 1 or 2 blown open transistor, failure of HCM, blown FU8, complete open of field power cable. On the other hand if it occurs during travel or intermittant, think, loose connection of field poer cables, loose connection of the t1,t2,t3 or t4 jumpers on field wiring board, or TM 1 or 2 failing under load or getting hot.
It should go without saying though that testing the battery and performing a frame ground test MUST be performed on any electric truck before troubleshooting further.
well with all electric trucks checking the battery and making sure it is in good condition and charged is the first thing.
But as techtrainer said there are many things that can cause this problem.
check your fuses (fu8) specifically.
If you remove the panel behind the operator it will expose the control panel and contactor panel. There are some large fuses on the panel connected to the buss bars, there is a 150A fuse connecting the B pos to field windings and auxiliary motor, you'll need to check this and make sure it is not open. You may as well check the other fuses too but FU8 is the fuse described in the troubleshooting manual for this code.
There are also cables to the field windings and field circuit to the HCM (H Bridge Control)
TM1 and TM2 could be bad
VM could be defective
Drive motor may have open windings
You will need the troubleshooting guide to get the info you need to troubleshoot this problem effectively.
But start with checking battery and fuses and connections on cables etc.
Are you getting this code key-on self test, or during use (driving)? The code is triggered because the VM (Vehicle Manager) is not seeing current flow in the field circuit of the drive motor during travel. There are a number of things that can cause this, but I would need to know first when the code is displayed.