I have a 98 za4 and I let it sit for about a month in the garage and it was driving fine I found out that my door was cracked and the battery died ok no prob jumped it off and it's good. Get on the highway 1 &2 are good it shifts to 3rd and at about 1.8k rpm feels like its in neutral if I back off I can feel it pulling under 2000rpm it was working fine before I sat it any suggestions?

 

I don't think this has anything to do with it being jumped; doesn't sound electrical. (Edit: starting to sound electrical after all.)
Have you checked the fluid level lately?
This sounds like the notorious 3-4 clutch problem, but I don't see why it would suddenly get worse from just sitting for a month.
Please verify the fluid level and that there are no "Check Engine" codes.

 

Pressure solenoid engine code

 

Hmmm, if the pressure solenoid is bad, the trans will default to max pressure which gives very firm shifts and would reduce slippage, not increase it.

I'll admit that this has gone over my head and hopefully a more experienced person has a good suggestion. This is starting to sound electrical after all.

If it were me, and I had no other suggestions, I would first disconnect the battery for 30 minutes and reconnect to reboot the PCM clean. I would then check the cable to the trans for damage due to rodents. If the problem and code persists, I would then replace all the solenoids and internal wiring harness (which are now 15 years old!) while replacing the fluid and filter. (About $120 for solenoids and harness, $10 for filter, $30+ for 5 quarts ATF).

Before doing any of that, perhaps someone else has a better idea or specific solution.

Ted.

 

Just re read codes and it's gone.. Added some lucas ATF and it seems to be doing better but only drove maybe a half mile since advanced is only right down the street from the job

 

Is it possible with the battery during my PCM lost the shift points?