For GM vehicles equipped with a 315 or 433 MHz Tire Pressure Monitoring (TPM) system, a "Sensor Relearn Procedure" must be performed after tire rotation, remote keyless entry receiver module replacement, or tire pressure sensor replacement. This relearning process can be performed using the special tool EL-50448. Also applies to 2014 GM models. Tire pressure sensors on 2012 and later models can only be read using certain designated diagnostic tools. Before the tire pressure monitoring system operates normally, the body control module must record the ID information of each tire pressure sensor position. After replacing the tire or wheel speed sensor, use the following method to register the tire pressure sensor. Step 1 - Enter the tire learn mode and place the shift lever in the "P" position. After the learning is completed, the turn signal light will illuminate for 3 seconds and the horn will beep twice. For some vehicles equipped with a tire pressure monitoring (TPM) system, after replacing the tire pressure sensor or remote keyless entry receiver module, a "sensor relearn procedure" must be performed. This relearn procedure can be performed using the special tool EL-50448. Compatible Vehicle List: General Motors models from 20102014. The deflation method has been validated on a 2011 Chevrolet Volt using the EL-50448 TPMS relearn tool, allowing programming of 4 TPMS sensors in under a minute. The EL-50448 can be used on GM 20102013 TPMS systems for programming. The package does not include a charger or battery.