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.
2004 Buick Century BaseFACTORY OEM SERVICE PROCEDURE
Control Units
CONTROL UNITS LOCATION
| Component | Location |
|---|---|
| Blower Motor Control Processor (W/ Auto A/C) | Behind right side of dash, in HVAC module. See Figure . |
| Body Control Module (BCM) | Behind left side of dash, left of steering column. See Figure . |
| Body Control Module (BCM) Connector | Below left side of dash. See Figure . |
| Cruise Control Module (CCM) | Front of left strut tower. See Figure . |
| Cruise Control Module (CCM) Connector | Front left strut tower. See Figure . |
| Electronic Brake Control Module (EBCM) | At left side of engine compartment, near strut tower. See Figure . |
| Electronic Brake Control Module (EBCM) Connector | Left side of engine compartment. See Figure . |
| Express Open Connector | At sunroof motor. See Figure . |
| Heated Seat Control Module (Driver) | Below driver's seat. See Figure . |
| Heated Seat Control Module (Front Passenger) | Below right front seat. |
| Heater-A/C Control Module | Lower center of dash. See Figure . |
| Heater-A/C Control Module Connector | Lower center of dash. See Figure . |
| HVAC Control Module | Lower center of dash. See Figure . |
| HVAC Control Module Connector | Lower center of dash. See Figure . |
| Ignition Control Module (ICM) (3.1L VIN J) | Top right side of engine. See Figure . |
| Ignition Control Module (ICM) (3.8L VIN K) | Top front of engine. See Figure . |
| Ignition Control Module (ICM) (3.8L VIN 1) | Top front of engine. See Figure . |
| Inflatable Restraint IP Module | Right side of dash. See Figure . |
| Inflatable Restraint Sensing & Diagnostic Module Connector | Center of floor pan. See Figure . |
| Inflatable Restraint Sensing & Diagnostic Module (SDM) | Below carpet, under right front seat. See Figure . |
| Inflatable Restraint Side Impact Sensor-LH | In left side of driver's seat. See Figure . |
| Inflatable Restraint Steering Wheel Module | In steering wheel. See Figure . |
| Inflatable Restraint Steering Wheel Module Coil | Behind steering wheel, in column. See Figure . |
| Powertrain Control Module (PCM) | Left front side of engine compartment, in air cleaner assembly. See Figure . |
| Radio Antenna Module | On rear window header panel, above headliner. See Figure . |
| Remote Control Door Lock Receiver (RCDLR) | Behind instrument cluster. See Figure . |
| Sun Roof Module (Express Open) | Center rear of sun roof. See Figure . |
| Turn Signal/Hazard Flasher Module | Below left side of dash. See Figure . |
| Vehicle Communication Interface Module (VCIM) | On rear of left rear wheelhouse. See Figure . |
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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