Chart No. 8, Overdrive Cancelation Function Wiring Circuit A/T

Overdrive is cancelled if the Resume switch is used, or if the vehicle speed drops 1 mph below the vehicle set speed. At this time, the signals to the control unit are cancelled. Drive will then be controlled in third gear.
Measure voltage at terminal No. 13 on 1990 models or terminal No. 10 on 1991 models, 4A/T control unit, with the overdrive switch in the On position. Voltage should measure 12 volts.
Measure voltage at terminal No. 14 on 1990 models or terminal No. 11 on 1991 models, overdrive switch, with the overdrive switch in the On position. Voltage should measure 12 volts.