What is the location of the coolant sensor on a 2004 gmc envoy

SOURCE: Coolant Temp Sensor

The sensor is located on the drivers side engine block...although you can see if from looking from the top of the engine, you would have to get under the vehicle and look up to replace it. Be aware that it takes a special tool to unscrew the old one and screw in the replacement.

SOURCE: check engine light on - 2003 gmc envoy XL

That code represents a lower than expected reading for temperature (coolant). First thing to do is check your coolant level, as if it is low, then the sensor can not read correctly. Second, you may have a thermostat that is stuck open, allowing the coolant to cool off too much. The sensor should be mounted on top of the engine, near the thermostat housing.

SOURCE: battery removal on a 2004 GMC Envoy

The battery is on the right side behind the fuse box. You need a metric set to undo the 3 screws. Theres one that attaches to the body, one to the bar that goes along the top, and theres one on the left side below the vacuum hose and air induction. After you've taken out those three, you should lift the whole thing out(battery and shroud) together. It's hard to take the shroud off before you lift the battery out. After that, you have to pry the shoud off the battery. The two terminals in the back make it hard. Then just go to any auto parts store and they'll give you a new one. 

SOURCE: Location of coolant temperature sensor on 2003 GMC

on the left front of the block by the alt. 4.2 L engine

SOURCE: check engine light....coolant temperature sensor

take altanator off and it is located right behind