My Jeep Grand Cherokee is trying to kill itself. I will try to explain this in detail so hopefully you can help me.
About a month ago my jeep threw the code 1495, the LDP being open or shorted condition. I drove it like that for a while and then it started to have problems starting sometimes. But it’s a very unique problem, because the first time it might not start and then if I try to start it the second time it usually starts, if I had the AC on, then I can turn it off and start it the second time and it kicks up easily. I don’t think it’s the AC problem but the selector where you pick if the defrost, feet or whatever. When I turn it off it starts up easier. So I think it has something to do with the vacuum.
Then about a week ago I towed a big u-haul from Idaho to Texas and at one point we had to stop for construction and he engine started to heat up, it got to like 240ish before I noticed, I just turned on the heater and cooled it down, no lights came on for like trans over temp or an overheating light. So I’m hoping it didn’t hurt anything. Now in Texas my jeep feels like it doesn’t want to kick down to 1st gear much. When I first start up the car and take off it takes off in 1st gear, but then once I start and stop it feels like it’s in 2nd gear or something… oh yea I hit a dead dear, but I don’t see any damage under the jeep at all. Well I decided to replace the LDP and I noticed a cracked vacuum hose on the top of the LDP. So I simply cut off the cracked portion and then installed it. Cleared the codes, then it threw 2 17 codes, like 1756 and something else but I cleared them and they haven’t showed back up. But now it’s still throwing the 1495 code and it has the starting problem and the starting off in 1st gear issue…. I feel like it has something to do with vacuum pressure because of turning off the AC selector. What do you think could cause this? This is a cluster of crazy problems. ANY help would be nice.

I can't tell from your post but if you have not you should start by replacing the Leak Detection Pump - the fault code indicates a problem with the LDP itself. The 1756 code is a transmission shift fault code.
Then check for proper operation of the radiator fan.
Also check the manifold vacuum with a vacuum gauge and the under carriage for loose hoses.

Post year and engine info.