Cadillac CTS (2003) – fuse box diagram
Year of production: 2003
Underhood Fuse Block
The underhood fuse block is located in the engine compartment on the passenger’s side of the vehicle.
| Relays | Usage |
| LO SPEED FAN RELAY MINI | Low Speed Fan Motor |
| HI SPEED FAN RELAY MINI | High Speed Fan Motor |
| ACCESSORY RELAY MINI | Accessory Power Outlets |
| S/P FAN RELAY MINI | Series/Parallel Fan |
| PARK LAMP RELAY MICRO | Parking Lamps |
| HORN RELAY MICRO | Horn |
| HI BEAM RELAY MICRO | High-Beam Headlamps |
| DRL RELAY MICRO – OPT | Daytime Running Lamps |
| LO BEAM RELAY/HID MINI – OPT | Low-Beam HID Headlamps (Option) |
| HDLP WASH RELAY MINI – OPT | Headlamp Washer Motor (Option) |
| CIGAR RELAY MINI | Cigarette Lighter (Option) |
| BLOWER RELAY MINI | Front Blower |
| FOG LAMP RELAY MICRO | Fog Lamps |
| MAIN RELAY MICRO | Powertrain/ECM |
| STARTER RELAY MINI | Starter Solenoid |
| CMP CLU RELAY MICRO | Compressor Clutch |
| IGN-1 RELAY MICRO | Ignition Switch (ON) |
| Wiring Harnesses | Usage |
| BODY W/H | Wiring Harness Connection |
| BODY W/H | Wiring Harness Connection |
| ENG W/H | Engine Wiring Harness Connection |
| J Cases | Usage |
| R REAR | RRPDB (Passenger’s Side Rear Power Distribution Box) |
| R REAR | RRPDB (Passenger’s Side Rear Power Distribution Box) |
| L REAR | LRPDB (Driver’s Side Rear Power Distribution Box) |
| L REAR | LRPDB (Driver’s Side Rear Power Distribution Box) |
| HI FAN | High Cooling Fan Motor |
| LO FAN | Low Cooling Fan Motor |
| BLOWER | PWM Fan Motor Assembly |
| STARTER | Starter Solenoid |
| EBCM | Electronic Brake Control Module |
| Mini Fuses | Usage |
| RT PARK | Passenger’s Side Taillamp Assembly, Front Sidemarker and Front Parking Lamp Assembly |
| HORN | Dual Horn Assembly |
| LT HI BEAM | Driver’s Side High-Beam Headlamp |
| LT LOW BEAM | Driver’s Side Low-Beam Headlamp |
| RT LOW BEAM | Passenger’s Side Low-Beam Headlamp |
| RT HI BEAM | Passenger’s Side High-Beam Headlamp |
| SPARE | Not Used |
| SPARE | Not Used |
| THEFT | ECM (Electronic Control Module), TCM (Transmission Control Module), PASS-Key III+ Module |
| LT PARK | Driver’s Side Taillamp Assembly, Front Sidemarker and Front Parking Lamp Assembly |
| LIC/DIMMING | Rear License Plate Assembly, DIM |
| DIM/ALDL | DIM, ALDL (Assembly Line Data Link) |
| FLASHER | Turn Signal/Hazard Flasher Module |
| MANIFOLD | Manifold Flaps 1 and 2, Air Mass Meter, Canister Purge Valve |
| STRG CTLS | Steering Wheel Control Pad, Headlamp Switch |
| HTR VLV/CLTCH | Heater Valve, Clutch Switch (Normal Closed), Clutch Switch (Normal Open), Jumper to Start Relay Coil for Automatic Transmission |
| WASH NOZ | Driver’s and Passenger’s Side Heated Washer Nozzles |
| ECM | Electronic Control Module |
| TCM/IPC | TCM, ECM and IPC (Instrument Panel Cluster) |
| SPARE | Not Used |
| IGN MOD | Front Bank Ignition Modules |
| ELEC PRNDL | Electronic PRNDL |
| TCC/ET | TCC/ET Brake Switch (Extended Travel), TCC/ET Brake Switch (Cruise Disable) |
| STOP LP SW | Stop Lamp Switch |
| IGN SW | Ignition Switch (Power to IGN-3 and CRANK) |
| VOLT CHECK | DIM (Dash Integration Module) |
| ECM/TCM | TCM (Transmission Control Module), ECM (Electronic Control Module), IPC (Instrument Panel Cluster), PASS-Key III+ Module |
| WPR MOD | Windshield Wiper Module Assembly |
| INJ | Fuel Injectors |
| COMP CLUTCH | Compressor Clutch |
| WPR SW | Windshield Wiper/Washer Switch |
| FOG LAMP | Fog Lamps |
| OUTLET | Center Console Accessory Power Outlet |
| POST 02 | Driver’s and Passenger’s Side Oxygen Sensors, LRPDB (Pusher Cooling Fan Relay) |
| I/P OUTLET | Instrument Panel Accessory Power Outlet |
| CCP | Climate Control Panel |
| PRE 02 | Driver’s and Passenger’s Side Oxygen Sensors, Transmission Output Speed Sensor |
| SPARE | Not Used |
| SPARE | Not Used |
| SPARE | Not Used |
| Circuit Breakers | Usage |
| HDLP WASH C/B – OPT | Headlamp Washer Motor (Option) |
Rear Underseat Fuse Block (Driver’s Side)
The driver’s side rear fuse block is located under the rear seat on the driver’s side of the vehicle. The rear seat cushion must be removed to access the rear fuse block.
| Relay | Usage |
| SPARE | Not Used |
| SPARE | Not Used |
| SPARE | Not Used |
| PUSHER FAN | Pusher Fan (Export Only) |
| L POSITION RELAY MICRO | Driver’s Side Position Lamp |
| R POSITION RELAY MICRO | Passenger’s Side Position Lamp |
| IGN 3 RELAY MICRO | Heated Seat Modules, Air Inlet Motor, Shifter Assembly |
| STANDING LAMP RLY MICRO | Control for Position Lamp Relays |
| TRK DR REL SOL RELAY MICRO | Trunk Release Motor |
| REV LAMP RELAY MICRO | ISRVM (Inside Rearview Mirror), License Plate Lamp Assembly |
| Minifuses | Usage |
| L FRT HTD SEAT MOD | Driver’s Heated Seat Module |
| MEM/ADAPT SEAT | Driver’s Power Seat Switch, Memory Seat Module |
| TRUNK DR RELEASE | Trunk Release Motor |
| REVERSE LAMP | ISRVM (Inside Rearview Mirror), License Plate Lamp Assembly |
| SPARE | Not Used |
| POSITION LAMP | Taillamp Assemblies, Front Position Lamp Assemblies |
| SPARE | Not Used |
| SPARE | Not Used |
| AUDIO | Radio, OnStar Module |
| SPARE | Not Used |
| REAR DR MOD | Rear Door Modules |
| SPARE | Not Used |
| DRIVER DR MOD | Driver’s Door Module |
| SPARE | Not Used |
| HDLP LEVELING | Headlamp Leveling System Chassis Sensors (Export Only) |
| EBCM | EBCM (Electronic Brake Control Module) |
| CCP | CCP (Climate Control Panel) |
| IGN 3 | Heated Seat Modules, Air Inlet Motor, Shifter Assembly |
| J Cases | Usage |
| AMP | Audio Amplifier |
| PUSHER FAN | Pusher Fan (Export Only) |
| Circuit Breakers | Usage |
| SEAT C/B | Power Seat Switches, Memory Seat Module |
Rear Underseat Fuse Block (Passenger’s Side)
The passenger’s side rear fuse block is located under the rear seat on the passenger’s side of the vehicle. The rear seat cushion must be removed to access the rear fuse block.
| Minifuses | Usage |
| INTERIOR LAMP | Hush Panel Lamps, Puddle Lamps, Overhead Courtesy Lamp Assembly |
| PSGR DR MOD | Right Front Passenger Door Module |
| RIM | RIM (Rear Integration Module), Ignition Switch, Key Lock Cylinder |
| REAR FOG LAMP | Rear Fog Lamps (Export Only) |
| SPARE | Not Used |
| NAV | TV Tuner Assembly (Export Only), VICS (Vehicle Information Communication System) Module |
| SPARE | Not Used |
| SPARE | Not Used |
| POWER SOUNDER | Power Sounder, Inclination Sensor |
| SPARE | Not Used |
| TRUNK LAMP | Trunk Lamp |
| FUEL PUMP MTR | Fuel Pump Motor |
| AFTERBOIL | Afterboil Heater Pump |
| R FRT HTD SEAT MOD | Passenger’s Side Heated Seat Module |
| SPARE | Not Used |
| SIR | SDM (Sensing Diagnostic Module) |
| RIM | ISRVM (Inside Rearview Mirror), Power Sounder, RIM, Passive Trunk Release Sensor |
| CANISTER VENT | Canister Vent Solenoid |
| SPARE | Not Used |
| Circuit Breakers | Usage |
| DR MOD PWR C/B | Door Modules |
| J Cases | Usage |
| REAR DEFOG | Rear Window Defogger Element |
| SUNROOF MOD | Power Sunroof Module |
| Relays | Usage |
| RAP RELAY MINI | Retained Accessory Power |
| SPARE | Not Used |
| REAR DEFOG RELAY MINI | Rear Window Defogger |
| SPARE | Not Used |
| AFTER BOIL MICRO | Afterboil Heater Pump |
| INT LAMP RELAY MICRO | Hush Panel Lamps, Puddle Lamps, Overhead Courtesy Lamp Assembly |
| IGN 1 RELAY MICRO | Ignition Switch |
| REAR FOG LAMP RLY MICRO | Rear Fog Lamps (Export Only) |
| FUEL PUMP MOTOR RLY MICRO | Fuel Pump Motor |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.