Programmable Speedometer/Odometer Module

The Programmable Speedometer/Odometer Module (PSOM) receives input from rear anti-lock brake speed sensor, which is mounted on rear axle differential housing. Vehicle speed (MPH) signal is output to PCM and speed control module. PSOM failure may cause harsh engagements, firm shift feel and abnormal shift schedule. Unexpected downshifts may occur at closed throttle. Abnormal TCC operation may also occur with engagement only at WOT. Transmission Control Indicator Light (TCIL) may flash.