1991-93 General Information
Ford Motor Company Computer Relearn Procedures
Thunderbirds (Cougars) All Models
Vehicles equipped with engine or transmission computers may require
a relearn procedure after the vehicle battery is disconnected. Many vehicle computers memorize
and store vehicle operation patterns for optimum driveability and performance. When the vehicle
battery is disconnected, this memory is lost. The computer will use default data until new data
from each key start is stored. As the computer memorizes vehicle operation for each new key start,
driveability is restored. Vehicle computers may memorize vehicles operation patterns for 40 or more key starts.
Customers often complain of driveability problems during the relearn stage because the vehicle acts
differently then before being serviced. Depending on the type of vehicle and how it is equipped,
the following complaints (driveability problems) may exist:
These symptoms and complaints should disappear after a number of drive
cycles have been memorized. To reduce the possibility of complaints, after any service which requires
battery power to be disconnected, vehicle should be road tested.
- Harsh Or Poor Shift Quality
- Rough Or Unstable Idle
- Hesitation Or Stumble
- Rich Or Lean Running
- Poor Fuel Mileage
Ensure all components are connected. Ensure transmission fluid level is
correct. Warm engine to normal operating temperature. If vehicle has been repaired, perform KOEO and
Continuous Memory Code Self-Test and ensure fault codes are not present.
Computer Relearn Procedures
Idle Relearn Procedure
Place automatic transmission in Park or manual transmission in Neutral position.
Ensure the emergency brake has been set and all accessories are turned off. Start engine and bring to normal
operating temperature. Allow manual transmission vehicle to idle in Neutral for one minute. Allow automatic
transmission to idle in Neutral for one minute and then to idle in Drive for one minute. Once initial relearn
is complete, process will be completed during normal driving. Always complete the procedure before returning
the vehicle to the customer.
Drive Cycle Test (AOD-E, AXOD & AXOD-E TRANSAXLES)
With transmission gear selector in Overdrive, moderately accelerate vehicle to 50 MPH for a minimum of 15 seconds. Transmission should be in 4th gear. While holding speed steady, lightly apply and release brake for about 5 seconds. Stop and park vehicle for a minimum of 20 seconds with transmission gear selector in Drive. Repeat procedure 5 times. Always complete the procedure before returning the vehicle to
Drive Cycle Test (E4OD)
With transmission gear selector in Drive, press Overdrive Cancel Switch (LED should light).
Moderately accelerate vehicle to 40 MPH for a minimum of 15 seconds (30 seconds above 4000-ft. elevation)
Transmission should be in 3rd gear. While holding speed steady, press Overdrive Cancel Switch (LED should go off)
and accelerate from 40 MPH to 50 MPH. Transmission should shift from 3rd gear to 4th gear. Hold speed steady for
15 seconds. While holding speed steady, lightly apply and release brakes enough to turn brake lights on. Maintain
50 MPH for about 5 seconds. Stop vehicle for a minimum of 20 seconds with transmission gear selector in Drive. Repeat
procedure 5 times. Always complete the procedure before returning the vehicle to the customer.