Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1999 GMC EnvoyFACTORY OEM SERVICE PROCEDURE
Component Locations
COMPONENT LOCATIONS
| Component | Location | ||
|---|---|---|---|
| Ambient Light Sensor | Below Right Front Speaker Grille | ||
| Body Bussed Electrical Center (BBEC) | Under Left End Of Instrument Panel, Near Fuse Block | ||
| Body Control Module (BCM) (1) | Lower Rear Of Instrument Panel, On Heater Case | ||
| Data Link Connector (DLC) | Under Lower Left Side Of Instrument Panel | ||
| Daytime Running Light (DRL) Relay | In Underhood Bussed Electrical Center | ||
| Door Lock Relay | In Body Bussed Electrical Center | ||
| Driver Door Unlock Relay | In Body Bussed Electrical Center | ||
| Ground Connection G200 | Under Lower Left End Of Instrument Panel, On Firewall | ||
| Headlight Ground Relay | In Underhood Bussed Electrical Center | ||
| Headlight Power Relay | In Underhood Bussed Electrical Center | ||
| Horn Relay | In Underhood Bussed Electrical Center | ||
| Inadvertent Power Relay | In Body Bussed Electrical Center | ||
| Instrument Panel Fuse Block | On Left End Of Instrument Panel | ||
| Liftglass Relay | In Body Bussed Electrical Center | ||
| Parking Light Relay | In Body Bussed Electrical Center | ||
| Powertrain Control Module/Vehicle Control Module (PCM/VCM) | Right Side Of Engine Compartment | ||
| Retained Accessory Power (RAP) Relay | In Underhood Bussed Electrical Center | ||
| Receiver Control Module | Left Side Of Instrument Panel, On Sound Insulator | ||
| Underhood Bussed Electrical Center (UBEC) | Underhood, On Left Inner Fenderwell | ||
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Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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