I bought the Blazer about 2 months ago and last week I went to drive it and the service engine light was on. I have one of those OBD2 Bluetooth scanners and is giving me code p1860. I read that code could be the TCC solenoid so I went ahead and had that replaced along with the oil and filter. The check engine light still comes on with the same code. If I reset the code it comes back on within a couple seconds as long as I'm not moving. if I reset it and start driving or reset it while I'm driving it will not come back on until I am stopped or almost stopped for 5 seconds or so. When I reset the light it shifts normal. If the light comes back on and it will shift hard again.