The Cadillac ESV, part of the second generation produced between 2003 and 2004, is a large luxury SUV known for its spacious interior, powerful engine options, and advanced features. Its electrical system, encompassing the fuse box and relay components, plays a critical role in ensuring the vehicle’s functionality and performance.
In the Cadillac ESV 2nd Generation, the fuse box contains multiple fuses that protect various electrical circuits throughout the vehicle. These circuits power essential components such as the engine control module, lighting systems, climate control, entertainment features, and more. Fuses are designed to break the circuit in the event of an electrical overload or short circuit, preventing damage to associated systems.
Relays in the Cadillac ESV act as electrically operated switches that control high-current circuits. They facilitate the precise activation and deactivation of functions such as the starter motor, fuel pump, air conditioning compressor, and power windows or seats. Efficient relay operation ensures optimal power distribution and reliable performance of the vehicle’s electrical systems.
Regular inspection and maintenance of the fuse box and relays are essential to ensure the Cadillac ESV operates smoothly. This includes checking fuses for signs of wear or damage, ensuring relay connections are secure, and promptly addressing any electrical issues that may arise. Proper care of these components helps maintain the vehicle’s electrical integrity, enhancing safety and driving satisfaction in the Cadillac ESV 2nd Generation (2003-2004).
MUST READ: DYI – How to Check Car Fuses?
(2003-2004) Cadillac ESV 2nd Gen 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 ESV 2nd Gen 2003-2004 fuse assignment
Year of production: 2003, 2004
Instrument Panel Fuse Block
The fuse block access door is on the driver’s side edge of the instrument panel. Pull off the cover to access the fuse block.
| Fuses | Usage |
| RR Wiper | Rear Window Wiper Switch |
| SEO ACCY | Special Equipment Option Accessory |
| WS WPR | Windshield Wipers |
| TBC ACCY | Truck Body Controller Accessory |
| IGN 3 | Ignition, Heated Seats |
| 4WD | Four-Wheel Drive System |
| HTR A/C | Climate Control System |
| LOCK | Power Door Lock Relay (Lock Function) |
| HVAC 1 | Inside Rearview Mirror, Climate Control System |
| L DOOR | Driver’s Door Harness Connection |
| CRUISE | Cruise Control |
| UNLOCK | Power Door Lock Relay (Unlock Function) |
| RR FOG LP | Rear Fog Lamp (Export Only) |
| BRAKE | Anti-Lock Brake System |
| DRIVER UNLOCK | Power Door Lock Relay (Driver’s Door Unlock Function) |
| IGN 0 | PCM, TCM |
| TBC IGN 0 | Truck Body Controller |
| VEH CHMSL | Vehicle and Trailer High Mounted Stoplamp |
| LT TRLR ST/TRN | Left Turn Signal/Stop Trailer |
| LT TRN | Left Turn Signals and Sidemarkers |
| VEH STOP | Vehicle Stoplamps, Brake Module, Electronic Throttle Control Module |
| RT TRLR ST/TRN | Right Turn Signal/Stop Trailer |
| RT TRN | Right Turn Signals and Sidemarkers |
| BODY | Harness Connector |
| DDM | Driver Door Module |
| AUX PWR 2 | Rear Cargo Area Power Outlets |
| LOCKS | Power Door Lock System |
| ECC | Rear Electronic Climate Control, Liftgate |
| TBC 2C | Truck Body Controller |
| FLASH | Flasher Module |
| CB LT DOORS | Left Power Window Circuit Breaker |
| TBC 2B | Truck Body Controller |
| TBC 2A | Truck Body Controller |
Center Instrument Panel Fuse Block
The center instrument panel utility block is located underneath the instrument panel, to the left of the steering column.
| Device | Usage |
| SEO | Special Equipment Option |
| TRAILER | Trailer Brake Wiring |
| UPFIT | Upfitter (Not Used) |
| SL RIDE | Ride Control Harness Connection |
| HDLR 2 | Headliner Wiring Connector |
| BODY | Body Wiring Connector |
| DEFOG | Rear Defogger Relay |
| HDLNR 1 | Headliner Wiring Connector 1 |
| SPARE RELAY | Not Used |
| CB SEAT | Driver and Passenger Seat Module Circuit Breaker |
| CB RT DOOR | Right Power Window Circuit Breaker |
| SPARE | Not Used |
| INFO | Infotainment Harness Connection |
Underhood Fuse Block
The underhood fuse block in the engine compartment on the driver’s side of the vehicle near the battery.
Lift the cover for access to the fuse/relay block.
- *1 — Gasoline Engine and Fuel Injection Rail #2.
- *2 — Gasoline Engine and Fuel Injection Rail #1.
- *3 — Gasoline Engine; Oxygen Sensors.
- *4 — Gasoline Engine; Oxygen Sensors.
- *5 — PCM Ignition
| Fuses | Usage |
| GLOW PLUG | Not Used |
| CUST FEED | Accessory Power |
| STUD #1 | Auxiliary Power |
| MBEC | Mid Bussed Electrical Center Power Feed, Front Seats, Right Doors |
| BLOWER | Front Climate Control Fan |
| LBEC | Left Bussed Electrical Center, Door Modules, Door Locks, Auxiliary Power Outlet—Rear Cargo Area and Instrument Panel |
| STUD 2 | Accessory Power/Trailer Wiring Brake Feed |
| ABS | Anti-Lock Brakes |
| VSES/ECAS | Vehicle Stability |
| IGN A | Ignition Power |
| IGN B | Ignition Power |
| LBEC 1 | Left Bussed Electrical Center, Left Doors, Truck Body Controller, Flasher Module |
| TRL PARK | Parking Lamps Trailer Wiring |
| RR PARK | Right Rear Parking and Sidemarker Lamps |
| LR PARK | Left Rear Parking and Sidemarker Lamps |
| PARK LP | Parking Lamps Relay |
| STARTER | Starter Relay |
| INTPARK | Interior Lamps |
| STOP LP | Stoplamps |
| TBC BATT | Truck Body Controller Battery Feed |
| SUNROOF | Sunroof |
| SEO B2 | Off-Road Lamps |
| 4WS | Vent Solenoid Canister/Quadrasteer Module Power |
| RR HVAC | Rear Climate Control |
| AUX PWR | Auxiliary Power Outlet — Console |
| IGN 1 | Ignition Relay |
| PCM 1 | Powertrain Control Module |
| ETC/ECM | Electronic Throttle Control, Electronic Brake Controller |
| IGN E | Instrument Panel Cluster, Air Conditioning Relay, Turn Signal/Hazard Switch, Starter Relay |
| RTD | Ride Control |
| TRL B/U | Backup Lamps Trailer Wiring |
| PCM B | Powertrain Control Module, Fuel Pump |
| F/PMP | Fuel Pump (Relay) |
| B/U LP | Back-up Lamps, Automatic Transmission Shift Lock Control System |
| RR DEFOG | Rear Window Defogger |
| HDLP-HI | Headlamp High Beam Relay |
| PRIME | Not Used |
| SIR | Supplemental Inflatable Restraint System |
| FRT PARK | Front Parking Lamps, Sidemarker Lamps |
| DRL | Daytime Running Lamps (Relay) |
| SEO IGN | Rear Defog Relay |
| TBC IGN1 | Truck Body Controller Ignition |
| HI HDLP-LT | High Beam Headlamp-Left |
| LH HID | Left Hand High Intensity Discharge Lamps |
| DRL | Daytime Running Lamps |
| IPC/DIC | Instrument Panel Cluster/Driver Information Center |
| HVAC/ECAS | Climate Control Controller |
| CIG LTR | Cigarette Lighter |
| HI HDLP-RT | High Beam Headlamp-Right |
| HDLP-LOW | Headlamp Low Beam Relay |
| A/C COMP | Air Conditioning Compressor |
| A/C COMP | Air Conditioning Compressor Relay |
| RR WPR | Rear Wiper/Washer |
| RADIO | Audio System |
| SEO B1 | Mid Bussed Electrical Center, HomeLink, Rear Heated Seats |
| LO HDLP-LT | Headlamp Low Beam-Left |
| BTSI | Brake Transmission Shift Interlock System |
| CRANK | Starting System |
| LO HDLP-RT | Headlamp Low Beam-Right |
| FOG LP | Fog Lamp Relay |
| FOG LP | Fog Lamps |
| HORN | Horn Relay |
| W/S WASH | Windshield and Rear Window Washer Pump Relay |
| W/S WASH | Windshield and Rear Window Washer Pump |
| INFO | OnStar/Rear Seat Entertainment |
| RADIO AMP | Radio Amplifier |
| RH HID | Right Hand High Intensity Discharge Lamp |
| HORN | Horn Fuse |
| EAP | Electric Adjustable Pedals |
| TREC | All-Wheel Drive Module |
| SBA | Supplemental Brake Assist |
Conclusion
For owners and enthusiasts of classic Cadillac ESV 2nd Gen 2003-2004, 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.
