Instrument Panel Fuse Block
The fuse block access door is on the driver’s side edge of the instrument panel.
| Name | 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, Auxiliary Battery |
| 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 |
| TBC 2C | Truck Body Controller |
| FLASH | Flasher Module |
| CB LT DOORS | Left Power Window Circuit Breaker |
| TBC 2B | Truck Body Controlle |
| TBC 2A | Truck Body Controlle |
Center Instrument Panel Utility Block
The center instrument panel utility block is located underneath the instrument panel, to the left of the steering column.
| Relay name | 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/relay center is located in the rear of the engine compartment near the brake fluid reservoir.
*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
| Name | Circuit protected |
| GLOW PLUG | Not Used |
| CUST FEED | Gasoline Accessory Power |
| STUD #1 | Auxiliary Power (Single Battery and Diesels Only)/Dual Battery (TP2) Do not install fuse |
| 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 Rela |
| 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 Controlle |
| 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 | Not Used |
| 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 | Not Used |
| EAP | Electric Adjustable Pedal |
| TREC | All-Wheel Drive Module |
| SBA | Supplemental Brake Assist |
Auxiliary Electric Cooling Fan Fuse Block
The auxiliary electric cooling fan fuse block is located in the engine compartment on the driver’s side of the vehicle next to the underhood fuse block.
| Fuses | Usage |
| COOL/FAN | Cooling Fan |
| COOL/FAN | Cooling Fan Relay Fuse |
| COOL/FAN | Cooling Fan Fuse |
| Relays | Usage |
| COOL/FAN 1 | Cooling Fan Relay 1 |
| COOL/FAN 3 | Cooling Fan Relay 3 |
| COOL/FAN 2 | Cooling Fan Relay 2 |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.