I have a 2002 Blazer 4wd ls. with 174,000 miles. I have the common 50-55 mph rpm surging issue were i guess its lock and unlocking the torque converter at constant throttle and speed. I have drained the pain and replace both shift solenoids, torque converter pulse mod soleniod and the tcc lock solenoid. This evening i took it for a drive and it hasn't fixed anything. Only things i have done to the truck is used maf cleaner and cleaned the maf when this started and when that didn't help changed the soleniods. Not sure what my next step is to solving this. I did some research and seen some people have updated their valve bodies. Im hoping i don't have to do this. The blazer does not throw a check engine light the abs light comes on occasionally about it. could this possibly be the tps or brake switch? all fuses are good. hoping it is a switch or something easy that is throwing the converter off. all input is appreciated. Im afraid to drive it with the problem as I don't want to spend $1400 on a replacement rebuilt trans.

 

thought i would have got some replies by now but I did find the tps to be bad the problem seems about gone but it still randomly slips it seems around t lock but did the tps make a huge difference. replacing the fuel filter tomorrow