Here is the procedure to check the trans fluid. You will need a compatible scan tool to monitor the trans temp.
Transmission Fluid Level Checking Procedure and Application Chart
· All with the ZF and GM automatic transmission
· Checking the fluid level may be necessary if there is evidence of a leak, a complaint related to fluid level or in the event repairs are made to the transmission.
USE ONLY THE TRANSMISSION FLUID THAT IS APPROVED FOR USE WITH THE SPECIFIC TRANSMISSION AS INDICATED IN THE FLUIDSAPPLICATION CHART. ALL OTHER FLUIDS WILL CAUSE NON WARRANTABLE TRANSMISSION DAMAGE.
Fluid Level Checking Procedure for all Transmissions without a Dipstick:
1. The transmission temperature must be between 30°C and 50°C before checking can begin. Use the DIS or the MODIC to determine the transmission temperature.
2. The vehicle must be level and without load. With the engine running, switch on the air conditioning. This will increase the idle speed and ensure that all oil passages in the transmission are filled with oil.
3. Step on the brake firmly, apply parking brake fully and move the selector lever through each gear position, pausing briefly in each gear.
4. With the engine running and the selector lever in Park position, remove the filler plug located on the transmission (see picture for location). If a small stream of oil runs out, the fluid level is correct.
5. If no oil runs out when the filler plug is removed, the fluid level is too low. Add oil until it starts to overflow.
6. With the engine running, reinstall the oil filler plug and tighten to proper torque. (Refer to section below for proper tightening torque)