The Buick LaCrosse, manufactured from 2017 to 2019, epitomizes Buick’s commitment to blending elegance with modern technology in the mid-size sedan segment. Its advanced electrical system includes essential components such as the fuse box and relays.
The fuse box in the Buick LaCrosse 2017–2019 houses fuses designed to protect electrical circuits from overloads and short circuits, ensuring the safety of critical components like headlights, taillights, and power windows. Relays, serving as electrically controlled switches, manage the flow of electricity to systems such as the starter motor, fuel pump, and cooling fans, ensuring efficient and reliable operation.
Additional sophisticated electrical components in the Buick LaCrosse of this era include advanced infotainment systems, climate control features, power-adjustable seats, and advanced driver assistance systems (ADAS). These features rely on a robust electrical infrastructure to enhance comfort, convenience, and safety for occupants.
Understanding the layout and function of the fuse box and relays is crucial for maintaining and troubleshooting the Buick LaCrosse 2017–2019’s electrical systems. Regular inspection and maintenance of these components help ensure the vehicle’s reliability and performance, maintaining its reputation as a luxurious and dependable sedan in Buick’s lineup.
(2017-2019) Buick LaCrosse 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.
Buick LaCrosse 2017-2019 fuse assignment
- Cigar lighter / power outlet fuses in the Buick LaCrosse are the fuses №. F37 (Auxiliary power outlet/Cigar lighter), №. 43 (Rear accessory power outlet) and №. 44 (Front accessory power outlet) in the Passenger compartment fuse box.
Year of production: 2017, 2018, 2019
Passenger compartment fuse box
Fuse Box Location
It is located in the instrument panel, behind the cover.
Fuse box diagram (2017, 2018)
Assignment of the fuses and relays in the Passenger compartment (2017, 2018)
| № | Description |
|---|---|
| F1 | Left window |
| F2 | Right window |
| F3 | Not used |
| F4 | HVAC blower |
| F5 | Battery 2 |
| F6 | Electric steering column |
| F7 | Not used |
| F8 | Battery 3 |
| F9 | Engine control module/Battery |
| F10 | Body control module 2 On/Off |
| F11 | Not used |
| F12 | Not used |
| F13 | Not used |
| F14 | Not used |
| F15 | Transmission control module On/Off |
| F16 | Amplifier |
| F17 | Not used |
| F18 | Battery 7 |
| F19 | Not used |
| F20 | Battery 1 |
| F21 | Battery 4 |
| F22 | Battery 6 |
| F23 | Electric steering column lock |
| F24 | 2017: Sensing and diagnostic module 2018: Airbag sensing diagnostic module/ Passenger sensing module |
| F25 | Diagnostic link |
| F26 | Not used |
| F27 | AC DC inverter |
| F28 | Not used |
| F29 | Body control module 8 |
| F30 | Overhead console |
| F31 | Steering wheel control |
| F32 | Not used |
| F33 | HVAC |
| F34 | Center gateway module |
| F35 | Integrated chassis control module |
| F36 | Charger |
| F37 | Auxiliary power outlet/Cigar lighter |
| F38 | OnStar |
| F39 | Monitor |
| F40 | Object detection |
| F41 | Body control module 1 On/Off |
| F42 | Radio |
| F43 | 2017: Circuit breaker 1 2018: Rear accessory power outlet |
| F44 | 2017: Circuit breaker 2 2018: Front accessory power outlet |
| Relays | |
| K1 | Not used |
| K2 | Retained accessory power |
| K3 | Not used |
| K4 | Not used |
| K5 | Logistics |
Fuse Box in the engine compartment
Fuse Box Location
Fuse box diagram (2017, 2018)
Assignment of the fuses and relays in the Engine compartment (2017, 2018)
| № | Description |
|---|---|
| 1 | Not used |
| 2 | Not used |
| 3 | ABS pump |
| 5 | AC DC inverter |
| 6 | Rear closure |
| 7 | Left corner lamp |
| 8 | Power windows/ Rearview mirror/ Power seats |
| 9 | Engine boost |
| 10 | 2017: Semi-active damping system 2018: Airbag sensing diagnostic module/Passenger sensing module – eAssist |
| 11 | DC DC Battery 1 |
| 12 | Rear window defogger |
| 13 | Heated mirrors |
| 14 | Not used |
| 15 | Passive entry/ Passive start |
| 16 | Front wipers |
| 17 | Passenger power seat |
| 18 | ABS valve |
| 19 | Driver power sea |
| 21 | Sunroof |
| 22 | Right corner lamp |
| 23 | Auto headlamp leveling |
| 24 | Not used |
| 26 | Transmission control module/Ignition |
| 27 | Instrument panel/ Ignition |
| 28 | Electronic precision shift/Ignition |
| 29 | Rear vision camera/ Ventilation |
| 30 | Malfunction indicator lamp/Shift solenoid |
| 32 | Canister vent solenoid |
| 33 | Front heated seats |
| 34 | 2017: Rear heated seat/ Vehicle body safety module/Energy storage system fan 2018: BSM (eAssist)/Fan control module/Damping control module (SADS) |
| 35 | Fog lamps |
| 36 | Fuel module |
| 38 | Not used |
| 39 | Not used |
| 40 | Steering columnn lock |
| 41 | Not used |
| 43 | Heated steering wheel |
| 44 | Headlamp leveling/ Rear seat ventilation |
| 45 | Not used |
| 46 | Engine control module/Ignition |
| 47 | Not used |
| 48 | Engine boost/Left cooling fan |
| 49 | DC DC battery 2/AWD |
| 50 | Not used |
| 51 | Not used |
| 52 | Not used |
| 53 | Not used |
| 54 | Not used |
| 55 | Not used |
| 56 | Not used |
| 57 | Transmission auxiliary pump |
| 58 | TRCM |
| 59 | High-beam headlamps |
| 60 | Cooling fan |
| 61 | Not used |
| 62 | Not used |
| 63 | Not used |
| 65 | A/C HEV |
| 67 | Not used |
| 68 | Not used |
| 69 | Right HID low-beam headlamps |
| 70 | Left HID low-beam headlamps |
| 72 | Starter pinion |
| 74 | Starter motor |
| 75 | Engine control module |
| 76 | Powertrain – off engine |
| 77 | Not used |
| 78 | Horn |
| 79 | Washer pump |
| 81 | Transmission control module/ Engine control module |
| 82 | Not used |
| 83 | Ignition coils |
| 84 | 2017: Powertrain – on engine 2018: Coil |
| 85 | Engine control module switch 2 |
| 86 | Engine control module switch 1 |
| 87 | SAI reaction pump |
| 88 | Aeroshutter |
| 89 | Headlamp washer |
| 91 | Not used |
| 92 | TPIM motor generator unit pump |
| 93 | Headlamp leveling |
| 95 | SAI reaction solenoid |
| 96 | Fuel heater |
| 97 | Not used |
| 99 | Coolant pump |
| Relays | |
| 4 | AC DC inverter |
| 20 | Rear defogger |
| 25 | Front wiper control |
| 31 | Run/Crank |
| 37 | Front wiper speed |
| 42 | Transmission auxiliary pump |
| 64 | A/C control |
| 66 | Powertrain |
| 71 | HID low-beam headlamps |
| 73 | Starter motor |
| 80 | Starter pinion |
| 90 | SAI reaction solenoid |
| 94 | Headlamp washer |
| 98 | SAI reaction pump |
Conclusion
For owners and enthusiasts of classic Buick LaCrosse models from 2017-2019, 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 Buick’s craftsmanship and innovation in the automotive industry during that era.
