My 2002 bmw x5 3.0 is very sluggish and sputters when trying to pick up speed, however, once it picks up speed, it is okay. The service engine indicator light is on. About a month or so ago, I inadvertantly put engine oil in where the ATF fluid should be. Could this be the source of my problem? Should I drain whats in the ATF out and refill with ATF fluid? Help!!!!

SOURCE: 2004 BMW X5. Engine sputter, no power, won't idle

Have you replaced the fuel filter?Air filter?

SOURCE: Service Engine Soon light on 2002 BMW X5

go back & sleep with the mechanic, that always works for my sister.

SOURCE: BMW X5 Trans Fail Safe Program,

sometimes it will clear if you turn the X5 off and restart it. however, it could be an early indication that the tranny is about to expire. i have had it happen and it cleared with a power cycle, but also had friends where it cleared for a few weeks/months and returned. this time it was really the transmission that went bad. if you can't get it to clear, then i'd suggest taking it to the dealer and have them plug into it to have a better look.

SOURCE: power steering fluid or ATF

Yes There Is ONLY ONE PLACE for Power Steering Fluid.

ZF Gemmer Steering

The ZF Gemmer steering is permanently filled with oil. There is no drain plug.

ZF Rack and Pinion Steering Without Power Assist

The ZF rack and pinion steering is lubricated for its service life and therefore does not require servicing.
In case of repair, steering components on E21 vehicles are to be lubricated with a sodium-based grease, with a temperature range of -30°C to +75°C .
Calypsol D 4024 BMW Part No.32 11 1 116 929

Ball and Nut or Rack and Pinion Power Steering

Only reputable brand Automatic Transmission Fluid (ATF) of Dexron® III formulation may be used for the power steering and power steering pump.
In case of brief hydraulic noise after starting at low outside temperatures, we recommend replacing the red ATF with green CHF or LHM oil (see below).

ZF Ball and Nut Power Steering with H31 System

The approved oils for BMW models with power steering and the H31 brake booster system are identical with those oils approved for power steering without the H31 system except for the following:

E32 models with self-leveling rear suspension and mutual oil supply tank in the engine compartment.
Countries with very low outside temperatures (e.g. Canada) had their power steering systems filled at the factory with Pentosin CHF 7.1 since 9/87 through 9/91. This is also to be used on vehicles built before 9/87.

Since 9/91, vehicles now use Pentosin CHF 11S instead of CHF 7.1.

Pentosin CHF 7.1 BMW Part No.81 22 1 468 879
Pentosin CHF 11S BMW Part No.82 11 1 468 041

These cars are marked with a pertinent label located close to the oil tank.

LHM oils (green color) of the following manufacturers may also be used instead of Pentosin (CHF 7.1):
Shell LHM
Castrol LHM
Exxon LHM

The mixing of CHF, LHM oils and ATF is not permitted.

Pentosin CHF 4548 was used on vehicles built before 9/87 but is no longer available. However, mixing of Pentosin CHF 7.1 with residual quantities of Pentosin CHF 4548 are permiffed in these earlier vehicles. Mixing of these two oils is not permitted for E32/E38 vehicles.

The hydraulic system for power steering and power-assisted brakes must be drained as completely as possible when changing from one type of oil to the other.
All oil supply reservoirs are marked with the type of oil being used - ATF or CHF.

SOURCE: 2002 BMW 530i service engine light on

It could be any number of things you will nee the codes read to be sure. If yor mileage is near one of the recommended services points 50,000, 100,000 or 150,000 this could be the cause. Again you won't know or sure ill codes are read Good Luck With This