1996 Ford Ranger Owner's Manual - Page 155

Driving Your Ranger Procedures for driving your vehicle will vary depending on which type of transmission your vehicle has. s an Automatic Overdrive Transmission 4R44E/4R55E s a manual transmission Automatic Transmission Operation (4R44E/4R55E) The 4R44E and 4R55E transmissions are electronically controlled four speed overdrive automatic transmissions with lockup torque converter. Transmission operation is controlled by the Powertrain Control Module (PCM). The PCM will automatically adjust transmission operation to make up for varying conditions. Several sensors located on the engine and transmission such as throttle position, engine speed, vehicle speed and transmission temperature are used by the PCM to shift the transmission into a higher or lower gear when required for the best performance and fuel economy. For example, you may notice that the transmission will upshift to a higher gear more quickly when the vehicle has not reached normal operating temperature. The PCM also controls the transmission's Torque Converter Clutch (TCC) to further raise vehicle performance and fuel economy. The TCC will engage when the transmission operating temperature and other conditions determined by the PCM have been met. Engagement of the clutch may be noted as a decrease in engine speed. To help in troubleshooting, the PCM continually performs self-tests on the electronic control system and, if any faults are detected, stores them in memory. The Overdrive Off Indicator Light (O/D OFF), which is located on the instrument cluster, may flash steadily if a malfunction has been detected. If the Overdrive Off Indicator Light is flashing, contact your Ford dealer as soon as possible. If this condition persists, damage to the transmission could occur. 155