Your Gmc car has an onboard diagnostic computer that will store trouble codes when there is something wrong with the vehicle's emissions control system. The emissions system is important and if it is malfunctioning,XTOOL HD900 it can dramatically affect the performance of the Gmc car engine. Once you've fixed the vehicle, you need to know how to reset the check engine light. To do this, you need a special tool available at most auto parts stores called an OBD scan tool.UCANDAS VDM2 The scan tool will have a feature that allows you to erase all stored engine codes, which will reset the check engine light.
Open the hood of the GMC and loosen the retaining nut on the negative battery cable clamp.
Slide the cable clamp off the negative battery terminal.
Wait 15 minutes,OBDSTAR X300M then reconnect the cable clamp.
Start the engine and run it for 5 to 10 minutes to allow your GMC vehicle to relearn its idle procedure.