This Blazer just threw a P0740. It has been surging rpm for a few weeks. I was also aware of a misfire on #1 dct so I was attributing the surging to this. I fixed the misfire dct with an adjustment to the plug gap.
There are times where I have shut the engine off exited the vehicle and later returned to a dead battery. The ignition will allow the key out when not in the steering lock position. This leaves the odometer display lit and I'm sure other accessories with power. The P0740 is a torque converter control solenoid code but I see in other posts the ignition switch is involved in this. Before I go pulling the trans pan to get to the wiring harness, I thought I might address the ignition switch. Any advice from experience will be appreciated.