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.
2003 Cadillac CTS AutomaticFACTORY OEM SERVICE PROCEDURE
Component Locations
COMPONENT LOCATIONS
| Component | Location |
|---|---|
| Accelerator Pedal Position Sensor | Above Accelerator Pedal |
| A/C Clutch Relay | In Underhood Fuse Block |
| Automatic Transmission Manual Shift Shaft Switch Assembly | Inside Transmission |
| Camshaft Position Sensor | Left Front Of Engine |
| Crankshaft Position Sensors | Lower Left Side Of Engine, Near Flywheel |
| Data Link Connector | Under Instrument Panel, Near Steering Column |
| Engine Control Module | Right Front Of Engine, Above Valve Cover |
| Engine Coolant Temperature Sensor | Top Rear Of Intake Manifold |
| EVAP Canister Purge Solenoid | Right Side Of Engine, Near Valve Cover |
| EVAP Canister Vent Solenoid | Beneath Rear Of Vehicle, Above Rear Differential |
| Fuel Injectors | In Intake Manifold |
| Fuel Pump Relay | In Right Rear Fuse Block |
| Fuel Tank Pressure Sensor | In Fuel Tank |
| Heated Oxygen Sensor (HO2S), Bank 1, Sensor 1 | Right Exhaust Pipe, Before Catalytic Converter |
| Heated Oxygen Sensor (HO2S), Bank 1, Sensor 2 | On Right Catalytic Converter |
| Heated Oxygen Sensor (HO2S), Bank 2, Sensor 1 | Left Exhaust Pipe Before Catalytic Converter |
| Heated Oxygen Sensor (HO2S), Bank 2, Sensor 2 | On Left Catalytic Converter |
| Ignition Control Modules | Top Right & Left Side Of Engine, Center Of Camshaft Covers |
| Intake Air Temperature Sensor | In MAF Sensor |
| Intake Manifold Runner Control Solenoid | Left Front Of Intake Manifold |
| Intake Manifold Tuning Valve Solenoid | Rear Side Of Intake Duct |
| Knock Sensor, Bank 1 | On Right Front Of Engine |
| Knock Sensor, Bank 2 | On Left Front Of Engine |
| Mass Airflow Sensor | Right Side Of Air Cleaner |
| Right Rear Fuse Block | In Passenger Compartment, Under Right Side Of Rear Seat Cushion |
| Throttle Position Sensor | Top Right Front Of Engine, Part Of Throttle Body Assembly |
| Transmission Control Module | Right Front Side Of Engine Compartment |
| Vehicle Speed Sensor (Manual Transmission Only) | On Rear Of Transmission Assembly |
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.