Vehicles equipped with engine and transmission computers may require a relearn procedure after the vehicle battery has been disconnected. Most vehicle computers memorize and store vehicle operational patterns. When the battery is disconnected, the information may be cleared. If the information is cleared, the computer will go into default mode in order to operate the vehicle. The vehicle computer will relearn operational patterns each time the vehicle is restarted. The relearning process may take up to 40 or more key cycles.
When a specific engine component is replaced, a relearn procedure may be required. If the relearn procedure is not performed, the vehicle may exhibit the following:
If an accessory component was replaced, a relearn procedure may also be required. The following systems and components may not work properly without a relearn procedure:
It is important to reset any DTC-s before performing the relearn procedure. Most relearn procedures can be performed with the use of an OBD-2 scan tool.
For battery removal, installation, and battery reconnection instructions, refer to Battery system, Battery, removal & installation, also Battery reconnect/relearn procedure.