Originally vehicle would crank, fire and run for 3 seconds then cut out.

Scanned the vehicle and it had no communication with the BCM, we eventually diagnosed it as a faulty BCM replaced with second hand one and the vehicle ran fine.

Two months later the vehicle on 3 occasions has had the same symptoms as above and not run for 10 minutes if you let the vehicle sit it will fire and run.

Brought the vehicle into our workshop to test and cant get it to fault with running, however at random it will not communicate with the ABS module and instrument cluster and put up numerous communication DTC's.