The code P0977 (https://www.yourmechanic.com/article/p0977-obd-ii-trouble-code-shift-solenoid-b-control-circuit-high-by-brady-klopfer) will set if the transmission control module (TCM) records an abnormal voltage reading from a shift solenoid in the transmission. A vehicle with the P0977 trouble code will generally be driveable but due to the potential...
