The Cadillac STS, produced between 2005 and 2011, is a luxury sedan known for its comfort, advanced technology, and powerful performance. Its electrical system, comprising the fuse box and relay components, is critical to its operation and reliability.
The fuse box in the Cadillac STS contains multiple fuses that protect various electrical circuits throughout the vehicle. These circuits power essential components such as the engine control module, lighting systems, infotainment features, climate control, and more. Fuses are designed to prevent damage by interrupting the flow of electricity in the event of an overload or short circuit.
Relays in the Cadillac STS act as electrically operated switches that control high-current circuits. They play a vital role in activating functions such as the starter motor, fuel pump, air conditioning compressor, and power windows or seats. By efficiently managing power distribution, relays help ensure that each component receives the correct voltage for optimal performance.
Regular maintenance of the fuse box and relays is crucial to keep the Cadillac STS running smoothly. This includes inspecting fuses for signs of wear or damage, ensuring relay connections are secure, and addressing any electrical issues promptly. Proper care of these components helps maintain the vehicle’s electrical integrity, enhancing safety and driving satisfaction in the Cadillac STS 2005-2011.
MUST READ: DYI – How to Check Car Fuses?
(2005-2011) Cadillac STS fuse box and relay with Diagram
WARNING
- Never replace a fuse with one that has a higher amperage rating.
- A fuse with a too-high amperage could damage the electrical part and cause a fire.
- On no account should fuses be repaired (e.g. patched up with tin foil or wire) as this may cause serious damage elsewhere in the electrical circuit or cause a fire.
- If a fuse blows repeatedly, do not keep replacing it. Instead, have the cause for the repeated short circuit or overload tracked and fixed.
- Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.
Cadillac STS 2005-2011 fuse assignment
- Cigar lighter / power outlet fuses in the Cadillac STS are located in the Engine compartment fuse box. 2005-2007 – see fuses “I/P OUTLET” (Front Auxiliary Outlet) and “OUTLET” (Rear Auxiliary Power Outlet). 2008-2011 – see fuses “FRT PWR OUTLET” (Front Accessory Power Outlet) and “AUX OUTLET” (Rear Accessory Power Outlet).
Year of production: 2005, 2006, 2007, 2008, 2009, 2010, 2011
Engine compartment
Passenger compartment
Two fuse boxes are located under the rear seats.
Fuse box diagrams
2005, 2006, 2007
Engine compartment
Assignment of the fuses and relays in the engine compartment (2005-2007)
| Name | Description |
|---|---|
| Fuses | |
| BLOWER | Blower Motor |
| R REAR | Passenger’s Side Rear Fuse Block |
| I/P OUTLET | Front Auxiliary Outlet |
| CCP | Climate Control, Headlamp Leveling |
| PRE O2/CAM | 2005-2006: Oxygen Sensor, CAM Phasers 2007: Oxygen Sensor, Variable Intake (V6), Purge Solenoid (V6), Camshaft Phasers (V6) |
| R REAR | Passenger’s Side Rear Fuse Block |
| WPR SW | Wiper/Washer Switch |
| FOG LAMP | Fog Lamps |
| OUTLET | Rear Auxiliary Power Outlet |
| EVEN COILS | Even Ignition Coils, Even Fuel Injectors |
| L REAR | Left Rear Fuse Block |
| WPR MOD | Wiper Module |
| POST O2 | Oxygen Sensor |
| COMP CLTCH | Air Conditioner Compressor Clutch |
| STARTER | Starter Solenoid |
| ABS | Anti-Lock Brake Pump |
| L REAR | Driver’s Side Rear Fuse Block |
| RAIN SSR | Rain Sensor, Headlamp Washer, Tire Pressure Monitor |
| CCP | Climate Control |
| SMT BM-OPT | Smart Beam Relay (Option) |
| EXT LIGHTS | Low Beam Relay, High Beam Relay, Park Lamp Relay |
| VOLT CHECK | Instrument Panel Module |
| ECM/TCM | Engine Control Module, Transmission Control Module, Easy Key Module, Instrument Panel Cluster |
| SPARE | Spare |
| LT PARK | Left Park Lamp, Left Taillamp |
| LIC DIMMING | License Plate, Instrument Panel Dimming |
| IPM ALDL | Instrument Panel Module Assembly Line Data Link Connector |
| HUD | 2005-2006: Heads-Up Display, Column Lock Module 2007: Heads-Up Display, Column Lock Module, Steering Column Switch |
| V8 ECM | 2005-2006: V8 ECM, Evap Solenoid 2007: V8 Engine Control Module (ECM), Evap. Solenoid, Vacuum Bypass |
| ABS | Anti-Lock Brake Controller |
| STR RLY | Starter Relay |
| WASH NOZ/AQS | Heated Washer Nozzles, Air Quality Sensor™ |
| ODD COILS | Odd Ignition Coils, Odd Fuel Injectors |
| TCM IPC | 2005-2006: Transmission, Instrument Panel, Engine Control 2007: Transmission Control Module (TCM), Instrument Panel, Engine Control |
| MAF | Mass Air Flow Sensor |
| HIGH FAN | Cooling Fan – High Speed |
| LOW FAN | Cooling Fan – Low Speed |
| RT PARK | Right Park Lamp, Right Taillamp |
| HORN | Horn |
| LT HI BEAM | Left Headlamp High Beam |
| LT LOW BEAM | Left Headlamp Low Beam |
| RT LOW BEAM | Right Headlamp Low Beam |
| RT HI BEAM | Right Headlamp High Beam |
| HFV6 ECM | 2005-2006: High Feature V6 Engine Control Module 2007: High Feature V6 Engine Control Module (ECM), Mass Air Flow Sensor (MAF) (V8) |
| HDLP WASH RELAY JUMPER -OPT | Headlamp Washer |
| Circuit brakers | |
| HDLP WASH C/B -OPT | Headlamp Washer (Option) |
| Relays | |
| STARTER RELAY MINI | Starter |
| SPARE | Spare |
| FOG LAMP RELAY MICRO | Fog Lamps |
| CMP CLU RELAY MICRO | A/C Compressor Clutch |
| BLOWER RELAY MINI | Front Blower Motor |
| POWERTRAIN RELAY MICRO | Engine Controls |
| RUN/CRANK RELAY MICRO | 2005-2006: Ignition 1 2007: Ignition 1, Starter, Washer Nozzle, Air Quality, Anti-lock Brake System, Climate Control Panel, Transmission Control Module, Instrument Panel Cluster, Mass Airflow Sensor, Engine Control Module |
| LOW SPEED FAN RELAY MINI | Cooling Fan Low Speed |
| ACCESSORY RELAY MINI | 2006-2006: Ignition 3 2007: Ignition 3, Rain Sensor, Headlamp Washer, Windshield Wiper/Washer Module |
| PARK LAMP RELAY MICRO | 2005-2006: Parking Lamps 2007: Parking Lamps, Instrument Panel Dimming, Rear License Plate Lamps |
| HIGH BEAM RELAY MICRO | Headlamp High-Beam |
| LOW BEAM RELAY/HID MINI-OPT | Low-Beam/High Intensity Discharge |
| HIGH SPEED FAN RELAY MINI | Cooling Fan High Speed |
| S/P FAN RELAY MINI | Cooling Fan Series/Parallel |
| HORN RELAY MICRO | Horn |
| Harness Connection | |
| ENG W/H | Engine Harness Connection |
| BODY W/H | Body Harness Connection |
| BODY W/H | Body Harness Connection |
Rear Underseat Fuse Box (Driver’s Side)
Assignment of the fuses and relays in the Rear Underseat Box (Driver’s Side) (2005-2007)
| Name | Description |
|---|---|
| Fuses | |
| AMP | Amplifier |
| INTERCOOLER PUMP | Intercooler Pump (Option) |
| THEFT/SHIFTER | Theft Sensors, Auto Shifter |
| MR-RTD MOD | MR-CVRTD Suspension Module (Option) |
| REAR DR MOD | Rear Door Modules |
| ELC SOL | 2005-2006: Exhaust Solenoid 2007: Automatic Level Control, Exhaust Solenoid (Option) |
| DRIVER DR MOD | 2005-2006: Driver Door Module 2007: Driver Door Module, Front Door SubWoofers (Option) |
| TV/VICS | Infotainment (Export Only) |
| REAR HTD SEATS | Rear Heated Seats |
| SPARE | Spare |
| SPARE | Spare |
| IGN3 | Front Passenger Heated Seat, Auto Shifter, Occupant Protection |
| RR SHLF SPEAKER | Rear Shelf Speaker (Option) |
| DPM | Memory Seat, Lumbar |
| TRUNK DR VALET | Trunk Release, Valet Lockout Switch |
| REVERSE LAMP | Reverse Lamps, Rear Parking Aid, Inside Rearview Mirror |
| AIR BAG | Airbag |
| POSITION LAMPS | Rear Taillamps |
| ELC RELAY | Automatic Level Control (Option) |
| Relays | |
| INTERCOOLER PUMP MICRO | Intercooler Pump (Option) |
| ELC RELAY | Automatic Level Control Compressor (Option) |
| L POSITION RELAY MICRO | Left Rear Taillamp, Position Lamps (Option) |
| TRUNK DR REL RELAY MICRO | Trunk Release Motor |
| REV LAMP RELAY MICRO | 2005-2006: Reverse Lamps, Rear Parking Aid 2007: Reverse Lamps, Rear Parking Aid, Inside Rearview Mirror |
| R POSITION RELAY MICRO | Right Rear Taillamp, Position Lamps (Option) |
| RUN RELAY MICRO | Ignition 3 |
| STNDBY LAMP RLY | Rear Taillamps, Position Lamps (Option) |
| Circuit Breakers | |
| SEATS C/B | Power Seat |
| Diode | |
| SPARE | Spare |
| Joint Connector | |
| JOINT CONNECTOR | Splice Pack (Green) |
Rear Underseat Fuse Box (Passenger’s Side)
Assignment of the fuses and relays in the Rear Underseat Box (Passenger’s Side) (2005-2007)
| Name | Description |
|---|---|
| Fuses | |
| SPARE | Spare |
| CANISTER VENT | Canister Vent Solenoid |
| RT TURN-RIM | Right Turn Signal |
| SUNROOF | Sunroof Module (Option) |
| STOP LAMPS | Stoplamps |
| FUEL PUMP | Fuel Pump |
| RF HTD ST/S-BAND | Front Passenger Heated Seat, S-Band Antenna |
| RADIO/ONSTAR | Radio/OnStar |
| AIR BAG | Airbags |
| RIM | Battery to Rear Integration Module |
| RUN/CRANK | 2005-2006: Ignition 1 2007: Ignition 1, Fog Lamps, Compressor Clutch, Engine Run/Crank Relays |
| HTD STG/CLM | Heated Steering Wheel, Column Lock Module |
| REAR DEFOG | Rear Defogger |
| INTERIOR LAMP | Interior Lamps |
| PSG DR MOD | Front Passenger Door Module |
| LT TURN-RIM | Left Turn Signal |
| REAR FOG LAMP (OPT) | Rear Fog Lamps (Option) |
| AFTERBOIL/DIFF PUMP | 2005-2006: After Boil Pump 2007: After Boil, Rear Differential Cooling Pump |
| RIM | Ignition to Rear Integration Module |
| Relays | |
| SPARE | Spare |
| REAR DEFOG RELAY MINI | Rear Defog |
| FUEL PUMP RELAY MICRO | Fuel Pump |
| REAR FOG LAMP RLY MICRO (OPT) | Rear Fog Lamps (Option) |
| STOP LAMP RELAY MICRO | Stoplamps |
| INT LAMP RELAY MICRO | Interior Lamps |
| RUN/CRANK RELAY MICRO | Ignition 1 |
| AFTERBOIL RELAY MICRO | After Boil Pump (Option) |
| Circuit Breakers | |
| WINDOW MTRS C/B | Power Window Motors Circuit Breaker |
| Diodes | |
| TRUNK DIODE | Trunk Release |
| Joint Connector | |
| JOINT CONNECTOR | Splice Pack (Blue) |
2008, 2009, 2010, 2011
Engine compartment
Assignment of the fuses and relays in the engine compartment (2008-2011)
| Name | Description |
|---|---|
| J-Case Fuses | |
| ABS MTR | ABS Module- ABS Module-StabiliTrak® |
| AFS | Active Front Steering |
| BLWR | Blower Motor |
| FAN 1 | Cooling Fan-Low Speed |
| FAN 2 | Cooling Fan-High Speed |
| LPDB 1 | Driver Side Rear Fuse Block |
| LPDB 2 | Driver Side Rear Fuse Block |
| RPDB 1 | Passenger Side Rear Fuse Block |
| RPDB 2 | Passenger Side Rear Fuse Block |
| SPARE | Spare |
| Mini Fuses | |
| A/C CLTCH | Air Conditioning Compressor Clutch |
| ABS | ABS Module-StabiliTrak® |
| ABS IGN | Antilock Brake Controller |
| AUX OUTLET | Rear Accessory Power Outlet |
| BRK VAC PUMP | Brake Vacuum Pump |
| CCP | Climate Control Panel |
| CCP/RLY COILS | Climate Control Panel, Headlamp Level Control, Active Cruise Control, Relay Coils, Starter, Front Blower |
| ECM 1 | Engine Control Module (ECM) |
| ECM/TCM BATT | ECM, Transmission Control Module (TCM) |
| ECM/TCM IGN | ECM, TCM, Instrument Panel Cluster |
| EKM/I/P MDL | Easy Key Module (EKM), Instrument Panel Module (I/P MDL) |
| EVEN COILS | Even Ignition Coils, Even Fuel Injectors |
| FOG LAMP | Front Fog Lamps |
| FRT PWR OUTLET | Front Accessory Power Outlet |
| FUEL COOL | Fuel Cooling |
| HORN | Horn |
| HTD WASH/AQS | Heated Headlamp Washer, Air Quality Sensor |
| HUD | Heads-Up Display, Steering Column Switch |
| I/BEAM | IntelliBeam Relay |
| I/P MDL/ALDL | Instrument Panel Module, Assembly Line Data Link Connector |
| LIC DIM | License Plate, Instrument Panel Dimming |
| LT HI BEAM | Driver Side High Beam Headlamp |
| LT LO BEAM | Driver Side Low Beam Headlamp |
| LT PRK | Driver Side Park Lamp/Driver Side Taillamp |
| ODD COILS | Odd Ignition Coils, Odd Fuel Injectors |
| POST O2 SNSR | Post Oxygen Sensor |
| PRE O2 SNSR | Pre Oxygen Sensor, CAM Sensors |
| RAIN SNSR/TPM | Rain Sensor, Relay Coil: Headlamp Wash |
| RT HI BEAM | Passenger Side High Beam Headlamp |
| RT LO BEAM | Passenger Side Low Beam Headlamp |
| RT PRK | Passenger Side Park Lamp, Passenger Side Taillamp |
| SPARE | Spare |
| V/CHK | Instrument Panel Module-Voltage Check |
| WPR | Wipe/Wash Module Assembly |
| WPR SW/VICS | Rain Sensor, Wiper Switch |
| Relays | |
| A/C CMPRSR CLTCH | Air Conditioning Compressor Clutch |
| ACCY | Accessory Rain Sensor, Headlamp Washer Relay Coil, Windshield Wiper/Washer Module |
| BRK VAC PUMP | Brake Vacuum Pump |
| FAN S/P | Cooling Fan Series/Parallel |
| FOG LAMP | Fog Lamps |
| FRT BLWR | Front Blower Motor |
| FUEL COOL | Fuel Cooling Pump |
| HI BEAM | High Beam Headlamp |
| HI FAN SPD | Cooling Fan High Speed |
| HORN | Horn |
| LO FAN SPD | Cooling Fan Low Speed |
| LOW BEAM W/O HID/HID | Low Beam Headlamp, High Intensity Discharge (HID) |
| PRK LAMP | Parking Lamps, Instrument Panel Dimming, Rear License Plate Lamps |
| PWR/TRN | Engine Controls |
| RUN CRNK | Heated Washer Nozzle, Air Quality, Antilock Brake System, Climate Control Panel, TCM, ECM, Instrument Control Panel, Instrument Control Panel Cluster |
| SPARE | Spare |
| STRTR | Starter |
| WPR HI | Windshield Wiper High Speed |
| Circuit Breakers | |
| HDLP WASH | Headlamp Washer Motor (Circuit Breaker) |
Rear Underseat Fuse Box (Driver’s Side)
Assignment of the fuses and relays in the Rear Underseat Box (Driver’s Side) (2008-2011)
| Name | Description |
|---|---|
| Fuses | |
| AMP | Amplifier |
| INCLR PUMP | Inner Cooler Pump (Option) |
| THEFT/SHFT | Theft Sensors, Auto Shifter, Power Sounder |
| MRTD MDL | Magnetic Ride Control Module (Option) |
| REAR DR MDL | Rear Door Modules |
| ELC EXH | Electronic Level Control, Exhaust Solenoid (Option) |
| DDM | Driver Door Module, Front Door SubWoofers (Option) |
| TV/VICS/SCM | Infotainment (Export Only), Supervisory Control Module (Option) |
| REAR HTD/SEATS | Rear Heated Seats |
| SPARE | Spare |
| IGN3 | Front Passenger Heated Seat, Auto Shifter, Occupant Protection, Electronic Tension Reducer for Seatbelt |
| REAR SHLF SPKR | Rear Shelf Speaker (Option) |
| MSM | Memory Seat Module Lumbar |
| TRUNK RELSE SW | Trunk Release, Valet Lockout Switch |
| BCK/UP LAMP | Reverse Lamps, Rear Parking Aid, Inside Rearview Mirrors |
| AIR BAG/BATT | Airbag |
| POS LAMPS | Rear Taillamps |
| ELC CMPRSR | Automatic Level Control (Option) |
| Relays | |
| INCLR PUMP | Inner Cooler Pump (Option) |
| ELC CMPRSR | Electronic Level Control, Compressor (Option) |
| LT POS | Left Rear Taillamp, Position Lamps (Option) |
| RT POS | Right Rear Taillamp, Position Lamps (Option) |
| RUN | Ignition 3 |
| STDBY LAMP | Rear Taillamps, Position Lamps (Option) |
| TRUNK RELSE | Trunk Release Motor |
| BCK/UP LAMP | Reverse Lamps, Rear Parking Aid, Inside Rearview Mirror |
| Circuit Breakers | |
| PWR SEATS | Power Seats |
| Diodes | |
| SPARE | Spare |
| Joint Connector | |
| J/C | Splice Pack (Green) |
Rear Underseat Fuse Box (Passenger’s Side)
Assignment of the fuses and relays in the Rear Underseat Box (Passenger’s Side) (2008-2011)
| Name | Description |
|---|---|
| Fuses | |
| AIRBAG/IGN | Sensing and Diagnostic Monitor, Automatic Occupant Sensor, Passenger Supplemental Inflatable Restraint |
| CNSTR/VENT | Canister Vent Solenoid |
| DIFF PUMP | Rear Differential Pump |
| FRT PDM | Front Passenger Door Module, Right Power Subwoofer |
| FUEL PUMP | Fuel Pump |
| HTD STR | Heated Steering Wheel |
| RF HTD/SEAT/XM | Front Passenger Heated Seat, S-Band™ Antenna |
| RDO/ONSTAR | Radio, OnStar® |
| INT LAMP | Interior Lamps |
| LT TRN/LDW | Left Turn Signal, Lane Departure Warning (Option) |
| REAR DEFOG | Rear Defogger |
| REAR/FOG | Rear Fog Lamps (Option) |
| RIM | Rear Integration Module |
| RIM /RPA /ISRVM /CLM | Rear Integration Module, Rear Parking Aid, Inside Rearview Mirror, Column Lock Module, Power Sounder, Active Front Steering (AFS), Supervisory Control Module |
| RUN/CRNK | UHBEC Run, CRNK Relay Coil, Rear Fog Lamp Relay Coil |
| S/ROOF | Sun Roof Module (Option) |
| SPARE | Spare |
| STOP LAMPS | Stop Lamps |
| RT TRN/SZBA | Right Turn Signal, Side Blind Zone Alert (Option) |
| Relays | |
| DIFF PUMP | Rear Differential Pump (Option) |
| FUEL PUMP | Fuel Pump |
| INT LAMP | Interior Lamps |
| REAR DEFOG | Rear Defogger |
| REAR/FOG | Rear Fog Lamps (Option) |
| RUN/CRNK | Ignition 1 |
| SPARE | Spare |
| STOP LAMP | Stop Lamp |
| Circuit Breakers | |
| WINDOW MTRS | Power Window Motors Circuit Breaker |
| Diodes | |
| TRUNK DIODE | Trunk Release |
| Joint Connector | |
| J/C | Splice Pack (Blue) |
Conclusion
For owners and enthusiasts of classic Cadillac STS 2005-2011, understanding the fuse box and relay systems is essential for vehicle maintenance. Regular inspection and maintenance of these components helped ensure the vehicle’s longevity and reliability, preserving its status as a symbol of Cadillac’s craftsmanship and innovation in the automotive industry during that era.
