Auto Trans Problem vr v8

[vs hay hauler]

(fix one problem find another)

Having a problem with the auto trans i hope some can help me with.
after 15 mins of driving in overdrive, auto cant seem to make up its mine whether to stay in over drive or not.on a flat road at 80ks revs go up by only 1-2 hundred rpm.
doesn't seem to be slipping, more like it cant make up it mind to stay or to change down.
auto has just been serviced, only had the car two days so i didn't pick up on this or mention it when it was serviced. the other thing that happens is the engine light comes on after this issue, which seems to help with this problem.car has error codes 41,59,72. any ideas

[Vee-ard]

Code 41 - Electronic Spark Timing Circuit (EST) Output Circuit Failure
Code 59 - Transmission Fluid Temperature - High - Auto Transmission Only
Code 72 - Vehicle Speed Sensor Signal Intermittent While Driving

The thing you're describing is the TCC not locking up properly in overdrive, it sounds like its locking and then unlocking constantly. This is probably related to your VSS being intermittent. Replace the module and would most likely fix it.

the auto transmission relies on the Throttle position sensor and VSS to tell it what gear it should be in. If it cant get a proper signal from both, its going to have problems.

[vs hay hauler]

thanks,
the tps sensor is located around the throttle body correct and where is the vss sensor located.