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 Saturn Ion Red LineFACTORY OEM SERVICE PROCEDURE
Control Units
CONTROL UNITS LOCATION
| Component | Location |
|---|---|
| Body Control Module (BCM) | At lower center of instrument panel. See Figure |
| Cruise Control Module (CCM) | Behind lower left side of dash, above brake pedal. See Figure. |
| Electronic Brake Control Module (ECBM) | At left side of engine compartment. See Figure. |
| Engine Control Module (ECM) (2.2L) | At left side of engine compartment. See Figure. |
| HVAC Control Assembly | At lower center of dash. See Figure. |
| Ignition Control Module (ICM) (2.2L) | At top rear of engine, near oil fill cap. See Figure. |
| Inflatable Restraint I/P Module | At right side of dash. See Figure. |
| Inflatable Restraint Module - Driver Side | In center of steering wheel. See Figure. |
| Inflatable Restraint Roof Rail Module (ASF) (Left) | At left rear side of roof bracket, in "C" pillar. |
| Inflatable Restraint Roof Rail Module (ASF) (Right) | At right rear side of roof bracket, in "C" pillar. See Figure. |
| Inflatable Restraint Sensing & Diagnostic Module (SDM) | Under center console, behind emergency brake. See Figure. |
| Inflatable Restraint Steering Wheel Module | On steering wheel. |
| I/P Module | Behind top right side of dash. See Figure. |
| Powertrain Control Module (PCM) (2.0L) | At rear of engine, near coolant overflow container. |
| Roof Rail Module-Left | On upper left "C" pillar. See Figure. |
| Roof Rail Module-Right | On upper right "C" pillar.Figure. |
| Sensing & Diagnostic Module (SDM) | Under center console. See Figure. |
| Steering Wheel Module | On steering wheel. See Figure. |
| Sunroof Module | Left of sun visor, in headliner. |
| Throttle Actuator Control (TAC) Module (2.0L) | On top left of engine, below supercharger. |
| Transmission Control Module (TCM) | At left rear of engine compartment. |
| Transmission Control Module (TCM) (2.2L) | At left rear of engine compartment, near strut tower. See Figure. |
| Vehicle Communication Interface Module (VCIM) | At center of rear package shelf, between rear speakers. See Figure. |
Factory Service Tools
Use the Manual With the Right Hardware
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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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