I then started bleed process, when I tried to proceed I got the message that DTC were present and they needed repaired before the test could continue. I am not understanding why ? Codes are cleared so how can it detect DTC?
I've run into the same issue with GM products. All the wheel speed sensor circuits MUST be working correctly for the bleed function to work. Even if you clear the fault codes and immediately launch into the bleed function, the EBCM can still detect a wheel speed sensor circuit fault. The wheel speed circuits are monitored at all times with the ignition on.
Irregardless, why would I have to repair unrelated dtc to do a bleed ?
Short answer is that the fault code is related because the GM engineer wanted it to be related.
If they didn't think it was related, they would have written the programming for the EBCM differently.
Why do they think it's related? I've always wondered the same. Liability, maybe? Never really got a satisfactory answer.
I assume I'm doing something wrong, please help. I have contacted Foxwell and they offer no assistance.
I really don't think you're doing anything wrong. You're just seeing the EBCM reacting to a fault the way it's programmed to. Even if Foxwell does answer, they won't be much help, as it's not really a scan tool problem.