First and foremost i hope you have checked the battery voltage and made sure you are working with a full charged battery, low voltage can cause these systems to go nuts at times.

But...............

if you have already done so and are following the troubleshooting manual for this EV system it also mentions checking the #22 and #25 snubbers for for shorted condition (which has already been suggested).
And while you're throwing parts at it ya might as well replace those as well.
Double check the connections on the choke wire running through the spiderblock, i've seen that connection behind the snubbers where the one screw is be faulty before because of faulty threading for the screw not letting it completly seat creating a loose connection. You can also check the connections in the plugs and even use a small pair of needle nose pliers and put a slight twist on the pins in the card to create a more positive connection. Sometimes these terminals in the plugs will open up and cause a bad connection and cause all sorts of codes that will run you around in circles.