Hello, i have a Komatsu FG25t-14 with a K21 Nissan engine-customer called for a no start, got to facility and unit started and ran-after 2-4 min idle changed, shut it off and would not re-start-checked fuel and ign system and found coils not firing (have + & - at the proper wires) which tells me ECU is not sending signal to coils. Tried the pedal dance till I wore holes in my shoe,(btw I am fairly proficient in the pedal dance) no diag port found. i suspect crank sensor. Is there any other way to try and read the codes on this unit? I don't want to start parts changing. Thanks for any help.