Hello and welcome to JustAnswer!
What kind of problem are you having?
P0700 sets in the engine controller when there is a code stored in the trans controller. This one is nothing to worry about.
The code pointing to the problem is the P0888. This code sets when there is no voltage on the trans relay output circuit. It will take some electrical testing to see what is happening.
It could be the trans relay. The first thing I would recommend is swapping it with another one and see if that helps.
It could be a loss of voltage to the trans relay. Be sure to check fuse 15 in the power distribution center. Replace the fuse if it's blown. If the fuse repeatedly blows then you have a short to ground on the relay's output circuit somewhere, which could be a shorted wire or internally shorted solenoid pack.
It could be an internal problem in the power distribution center.
It could be an open circuit after the circuit leaves the power distribution center.
It could be an internal problem in the TCM, which is a part of the powertrain control module (PCM). The PCM is located in the front of the left front wheel well. It's very unlikely that the problem is internal in the PCM.
The PCM is in the front of the left front wheel well. To access it you would raise and support the van and remove the left front wheel. Remove the three screws hold the fender liner to the bumper cover and remove the two push in clips holding the liner to the inner part of the wheel well. Peel the fender liner back in the front and you will expose a silver rectangular module with four 38-way electrical connectors, it's the only electrical part in that area. This is the PCM.