ECM swap and truck won't start

[dansdieselp]

Flashed a good ECM with a dsp5 tune. The oem tune was pulled from customers truck when I saw him last. Shipped him the ECM and switch. He installed the switch and ECM. Truck will crank, but won't start. The truck I used to flash it with started fine. What could the problem be?

[Tordne]

VATS Relearn?

[dansdieselp]

That's kind of what I was thinking, but I would of thought using the oem tune would have avoided that problem. Other thing is the customer is not close to me so doing the VATS relearn would be difficult.

[GMPX]

Dan, the VATS codes for the truck is not stored in the area of the ECM that is reprogrammed, it will still have the VATS codes in it from the truck the ECM came off. A VATS learn (or VATS off) is the only solution.
I am told your customer can do this without a scantool, just key on for 15 mins, key off for 30 seconds, repeat 3 times and it should start.

[dansdieselp]

Thanks Ross. I'll have him try the relearn. If not he's gonna send it back and I'll turn the vats off.

[dansdieselp]

Ross the key relearn worked great. Customer is up and running. Thanks.