My name is Shawn shop Automatic Transmission and Custom Exhaust center owner. Just recently purchased Pico scope kit 4 channel advanced kit from Autonerdz. i had never used a lab scope as a primary diagnostic tool in the past but i like the fact this tool can help verify the failure and it gets me away from the snap-on scanner solus ultra 14.2 that i use daily. Anyways customer brought this 1995 Suburban 5.7 4x4 in another shop in northern Florida had just rebuilt the transmission customer brought it back to them with a complaint of dropping out of O/D. the other shop had truck month could not verify the problem. The customer came to me frusterated said please keep the truck untill you can figure it out. so I started driving home nightly living about 30 miles away makes for long road test with stop and go and 60-70mph speeds. Once this truck has been driven about 12-15 miles The PROBLEM starts first symptom I notice it starts out with shift points late and once in overdrive and torque converter has engaged 100% the truck starts to drop in and out of lock up then drops in and out of overdrive and if the shifter is left in the overdrive position will just blow into nuetral like it has lost 4th gear. take the shifter put it in manual 3rd starts dropping out of 3rd if you step down on the gas 3rd will hold but under light or steady speeds will cycle in out. have replaced the range sensor , shift solenoid A&B Also note the ABS light is staying on and the brake light seems to flicker off and on during the 3rd and 4th gear issues but VSS shows no drop outs on scanner data pids. Anyone have any recomendations on using the pico scope to figure this out was gonna put shift solenoid A & B on channels 1 and 2 and watch if maybe tcm was turning them off ? IM NEW TO THE FORUM ANY THOUGHTS OR ADVICE WOULD BE REALLY COOL AND APPRECIATED VERY MUCH. THANKS FOR READING MY POST