This is a bit late, but perhaps it will help. From the service manual

4. Actuate the parking brake. Start engine and let it run at idle speed in selector lever position “P”.
5. Shift through the transmission modes several times with the vehicle stationary and the engine idling
6. Warm up the transmission, wait at least 2 minutes and check the oil level with the engine running. Push the Special Tool 8863A (1) in up to the stop and pull out again, read off oil level, repeat if necessary.
7. Check the transmission oil temperature. NEED THE DRBIII SCAN TOOL TO KNOW THE EXACT TEMP
Note: The true transmission oil temperature can only be read by a scan tool in REVERSE or any forward gear position.
8. The transmission Special Tool 8863A has indicator marks every 10mm. Determine the height of the oil level on the dipstick and using the height, the transmission temperature, and the Transmission Fluid Graph, determine if the transmission oil level is correct.
9. Add or remove oil as necessary and recheck the oil level.