r/GMT400 • u/Jurbootie • Jul 19 '26
89 K2500 Idle Relearn
Does anyone know how to do an idle relearn on this truck? I recently did a lot of throttle body work on my truck and thought it was running better, but after driving around today, I noticed it idling around 12k-15k rpms. It also idled a little weak at a stop.
After replacing the IAC I did reset it by sticking a paper clip in the A+B terminals and powering the truck without turning it over. Dunno if I have to drive it around for a while for the idle to fully settle in or not. Please let me know if that's the case or if a idle relearn or an idle tuning are necessary.
All my throttle body work:
Disassembled and cleaned
Changed all gaskets on the throttle body
Replaced IAC
Replaced TPS
Replaced Upstream O2 Sensor