no overdrive

95 riviera wont go into overdrive there is no engine light on
is there a relay for the torque converter clutch
3 relays on firewall does anyone know what they are for
and also can i have a bad TPS without it throwing a code

thanks for your help

There is not an external relay for the TCC solenoid! The PCM Quad drivers (mini relays) inside the PCM, handle that function. Usually the TPS will give a fault if out of spec.

i agree tps you woudn't think a little sensor like that would do it.but it did for a guy i worked on his car he never belived me until i put it on.also cured it right up.and he lost his 50 bucks to.