Code P026, Shorted Throttle Position Switch Circuit: Notes
WARNING: This page is about a different car, the 1995 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Throttle position switch is part of ISC motor assembly. PCM provides a 5-volt reference signal on circuit No. 427. When throttle lever contacts ISC plunger, throttle switch closes. When throttle switch is closed, input voltage is low. Code P026 sets when PCM sees a TP sensor signal greater than 16 degrees (accelerator applied) but throttle switch remains closed.