how do i know if my nissan maxima is a 4 or 5 speed automatic transmission

Automatic=4 speed-----Manual 5 or 6 speed~

You'd have to phone the dealer with the vin and ask them unless you know how to read the tags on the transmission but it's most likely a 5 speed.

All 2004 Nissan Maxima SL models built between January of 2003 and February 5, 2004 have the 4-speed automatic transmission. All 2004 SL models built between February 6, 2004 and July 2004 (end of '04 run) have the 5-speed auto tiptronic (same as the Maxima SE) transmission. All 2004 Nissan Maxima SE models have the 5-speed transmission.

The 4 speed automatic transmissions have the starter on top of the transmission. Also the 5 speed automatic transmissions will have a black cover on the transmission running vertical with an oil cooler next to it under the battery tray that houses all of the solenoids. The 5 speeds can also be identified by a grouping of three plugs on top of the transmission.