This truck has a K21 engine, I got a E27 code refering to a faulty crank sensor. We tuned the machine, erased the code and the code came back. The forklift started, idled ok, but coughed when the accelerator was punched 25% of the time.

The customer ran the truck for 1 hour, shut the machine down and it wouldn't restart. Returned and checked the codes, F04, and P04, ECM communication error, now showed.

Any ideas? Could the faulty cranksensor have completely broke causing this issue? Will sensor replacement correct the issue? These 2 codes were the only 2 codes displayed, E27 didnot show when the truck would not restart?

Thank you,

JOHN