So I have a 2001 Freightliner FL 70 service truck. Serial # 1FVABSAK52HJ65268. It has a Cat 3126. Serial # 9SZ06948. It will turn over but will not start. Our laptop will not communicate with the ECU. With the key on, the message on the LED screen on the dash reads:
No Engine
SID 254
Fail 07
When I turn the key to start, the message reads:
No engine
ICU 140
ABS 136
I have changed fuel filters, HEUI pump, and swapped out ECUs with a like known running service truck. I have…