Yin

My MDX 2007-Cannot Start together with TPMS and Check SH-AWD System Warnings.
I drove outside for shopping, then came back to the car to start.
The key switched on but with two warnings: TPMS and Check SH-AWD System Warnings.
The key could be turned to the start position but nothing happened. The screen was still on normally.
Having tried many times, the car was still no reaction. No crank of starter, no other signs, but the two warnings.
I had a tow truck to take it back to my home.
Then I tried again the car worked. This kind of strange happened twice. First day I restarted again after a few times trials.
The second day I failed.
Can anybody help me? Before I find the root cause, I dare not driving it outside, except without stopping the engine.

Thank you!