Engine Room Junction & Relay Blocks
WARNING: This page is about a different car, the 2003 Toyota Highlander and 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Numerous junction, relay and fusible link blocks are located in the engine room. See Fig 1. For identification of current flow, see Fig 2.
Component Locations
- The anti-lock brake system (ABS) relay block is located on left rear of engine compartment. See Fig 1. For identification of ABS relay block components, see Fig 3. For wiring diagram of ABS relay block circuit components, see ANTI-LOCK BRAKES in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Engine room fusible link block is located at left side of engine room. See Fig 1. Engine room fusible link block contains fusible links. For identification of fusible link block components, see Fig 4. For identification of fusible link block fuse components, see table below. The engine room fusible link block is the connection point for various wiring harnesses. For wiring diagrams of engine room fusible link block circuit components, see appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Engine room junction block is located at left side of engine room. See Fig 1. Engine room junction block contains relays and fuses. For identification of engine room junction block components, see Fig 5. For identification of engine room junction block fuse components, see table below. The engine room junction block is the connection point for various wiring harnesses. For wiring diagrams of engine room junction block circuit components, see appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Engine room relay block No. 2 is located at left side of engine room. See Fig 1. Engine room relay block No. 2 contains relays and fuses. For identification of engine room relay block No. 2 components, see Fig 6. For identification of engine room relay block No. 2 fuse components, see table below. The engine room relay block is the connection point for various wiring harnesses. For wiring diagrams of engine room relay block No. 2 circuit components, see appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- The Engine Room relay block No. 3 is located at right front of engine room. See Fig 1. The Engine Room relay block No. 3 contains the relays for the daytime running lights and a fuse. See Fig 7. For identification of Engine Room Relay Block No. 3 Fuse Components, see Fig 7. For wiring diagrams of engine room relay block No. 3 circuit components, see HEADLIGHTS in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
INSTRUMENT PANEL RELAY IDENTIFICATION
| RELAY DESCRIPTION |
|---|
| Engine Room Relay Block No. 2 |
| Engine Room Relay Block No. 3 |
| ABS Relay Block |
| Heater Relay |
ANTI-LOCK RELAY BLOCK RELAY IDENTIFICATION
| RELAY DESCRIPTION |
|---|
| SKID Control Relay |
FUSIBLE LINK BLOCK FUSE IDENTIFICATION LEGEND
| Fuse | System | |
|---|---|---|
| 30A | AM2 | Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) Starting and Ignition |
| 30A | CDS | Radiator Fan and Condenser Fan (1 MZ-FE) Radiator Fan and Condenser Fan (2AZ-FE) |
| 30A | RDI | Radiator Fan and Condenser Fan (1 MZ-FE) Radiator Fan and Condenser Fan (2AZ-FE) |
| 30A | RR DEF | Rear Window Defogger |
| 40A | ABS1 | ABS VSC |
| 40A | ABS2 | ABS VSC |
| 50A | HEATER | Air Conditioning (Automatic A/C) Air Conditioning (Manual A/C) |
| 140A | ALT | Automatic Light Control Charging Illumination Light Auto Turn Off Power Outlet Power Seat Radiator Fan and Condenser Fan (1 MZ-FE) Radiator Fan and Condenser Fan (2AZ-FE) Taillight |
ENGINE ROOM JUNCTION BLOCK RELAY IDENTIFICATION
| RELAY NUMBER | RELAY DESCRIPTION |
|---|---|
| A. | Head Relay |
| B. | - Relay |
| C. | RR DEF Relay |
| D. | M/G CLT Relay |
| E. | Horn Relay |
| F. | EFI Relay |
ENGINE ROOM JUNCTION BLOCK FUSE IDENTIFICATION LEGEND
| Fuse | System | |
|---|---|---|
| 7.5A | ALT-S | Charging |
| 7.5A | ECU-B | Air Conditioning (Automatic A/C) Air Conditioning (Manual A/C) Automatic Light Control Combination Meter Door Lock Control Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) Front Fog Light Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) Interior Light Key Reminder and Seat Belt Warning Light Auto Turn Off Power Window Theft Deterrent System VSC Wireless Door Lock Control |
| 10A | DOME | Combination Meter Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) Garage Door Opener Interior Light |
| 10A | DOME | Key Reminder and Seat Belt Warning Wireless Door Lock Control |
| 10A | HEAD LP LH UPR | Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) |
| 10A | HEAD LP RH UPR | Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) |
| 10A | HORN | Horn Theft Deterrent System |
| 15A | HAZARD | Trailer Towing Turn Signal and Hazard Warning Light |
| 15A | SECURITY | Theft Deterrent System |
| 20A | EFI | Electronically Controlled Transmission and A/T Indicator (1 MZ-FE) Electronically Controlled Transmission and A/T Indicator (2AZ-FE) Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) |
| 20A | TOWING | Trailer Towing |
| 25A | DOOR LOCK | Door Lock Control Theft Deterrent System Wireless Door Lock Control |
| 25A | RADIO NO.1 | Radio and Player (6 Speaker) Radio and Player (8 Speaker) |
| 40A | MAIN | Automatic Light Control Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) Light Auto Turn Off Theft Deterrent System |
ENGINE ROOM RELAY BLOCK NO. 2 RELAY IDENTIFICATION
| RELAY NUMBER | RELAY DESCRIPTION |
|---|---|
| A. | ABS MTR |
| B. | ABS SOL |
| C. | A/F HTR |
| D. | Fan RLY No. 2 |
| E. | - |
| F. | Fan RLY No. 1 |
| G. | ST RLY |
| H. | Fan RLY No. 3 |
ENGINE ROOM RELAY BLOCK NO. 2 FUSE IDENTIFICATION LEGEND
| Fuse | System | |
|---|---|---|
| 7.5A | ABS3 | ABS VSC |
| 7.5A | STARTER | Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) Starting and Ignition |
| 15A | HEAD LP LH LWR | Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) |
| 15A | HEAD LP RH LWR | Combination Meter Headlight (w/ Daytime Running Light) Headlight (w/o Daytime Running Light) |
| 25A | A/F | Engine Control and Engine Immobiliser System (1 MZ-FE) Engine Control and Engine Immobiliser System (2AZ-FE) |
ENGINE ROOM RELAY BLOCK NO. 3 RELAY IDENTIFICATION
| RELAY DESCRIPTION |
|---|
| DRL No.3 Relay |
| DRL No.4 Relay |
| DRL No.2 Relay |