Lightning bolt light comes on and off sporadically

[Larry H]

Been having the lightning bolt light coming on and off repeatedly.  Doesn't stay on long mostly when under a load but if you ease up just a little on the throttle sometimes it goes right out. Tried to blink check it and will only blink codes when the light is on. Truck seems to be running fine all gages are reading good.  Have gotten a 3-5, 6-4, 6-5, 3-2 it's all over the place. Any ideas on where to start? 

[Joey Mack]

you have timing code and engine brake code and comm. codes...  do you have oil in the EECU plug? also,, what year and engine please. I assume 04-06 aset c engine....  jojo

[Larry H]

Yep 04 ac427 aset cx613 driving me crazy just got it working and now it's throwing that light most of the time it's only on for a couple seconds longest it's been on constantly is about 15 to twenty seconds.

[Joey Mack]

check all the engine grounds...... is the eecu secured?   i just put one of these together and cranked it today....  lots of sensors.. jojo

[Larry H]

I'll check it tomorrow,  I checked my grounds at the batteries today on my break , going to check all my connections tomorrow.  Seen someone say the main power relay may be going bad and breaking down with the engine heat. Going to try checking those tomorrow also. Just trying to get a starting point,  seems to be a common problem. 

[Larry H]

I'll check those out tomorrow too, I've been afraid to stretch her legs so I've been running super short loads but gotta get her moving and making more money. Thanks for the response Joey Mack I  appreciate the starting points

[Joey Mack]

there are grounds on the frame behind the left steer tire. they go to the block, in front of the starter.  there should be a ground breaker on the firewall next to the starter relay, it's black and about 2" in diameter.  the EECU fuse # is 40, it's in the epdm/fuse box that is next to the steering shaft under the hood... make sure it's clean and tightly in the socket...   jojo