1997 Ford Ranger Owner Guide 1st Printing - Page 164

Driving Automatic Transmission Operation (4R44E/5R55E) If your vehicle is equipped with an automatic transmission, it will be either a four speed overdrive transmission (4R44E) or a five speed overdrive transmission (5R55E). All 2.3L and 3.0L engines use the 4R44E transmission, while all 4.0L engines use the 5R55E transmission. Both transmission types have a 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 Transmission Control Indicator Light (TCIL) (O/D OFF), which is located on the instrument cluster, may flash steadily if a malfunction has been detected. If the TCIL is flashing, contact your Ford dealer as soon as possible. If this condition persists, damage to the transmission could occur. 163