2003 TOYOTA TACOMA (EWD517U) 104 HEADLIGHT (w/ DAYTIME RUNNING LIGHT) 16 OFF TAIL HEAD LOW HIGH FLASH DIMMER SW LIGHT CONTROL SW 222 12 3 12 3 1111 3322 L–R B–Y L 2 10A HEAD ( LO LH ) 10A HEAD ( HI LH ) 10A HEAD ( LO RH ) 10A HEAD ( HI RH ) G 2 2 4 213 DIMMER RELAY 13 24 IE 13 24 1 2 22 22 IF1 2 22 R–W V–Y G–Y G–Y W R–G B–Y V G–Y G–Y W–G W–G W W–R L W–R V–Y R–W L W–G W–G 87 BATTERY DIODE ( DAYTIME RUNNING LIGHT SYSTEM ) D13 DAYTIME RUNNING LIGHT RELAY NO. 4 D 9 HEADLIGHT RH H 2 HEADLIGHT LH H 1 HEAD RELAY C14 COMBINATION SW 2 2 IF111 G–W G–W 3A16 3A13 3A17 W–G W–B W–G W–B B B B B I 9 W–B W–BW–B 7. 5A DRL E 3 B–Y B–Y B–Y B–Y 2 2 1 AAAA BC JUNCTION CONNECTOR BJ 9 A , J10 V G–Y 1L14 1L13 13 BODY ECU JUNCTION CONNECTOR J 1 G–Y R–G 1B7 1E4 1B 5 W–B W–B W–G 2003 TOYOTA TACOMA (EWD517U) 105 5 10A GAUGE 2 1 2 1 FROM POWER SOURCE SYSTEM ( SEE PAGE 54 ) IF1 6 R–W V–Y G–Y W–B B–R V G–Y V–Y W–B W–B G–W G–W R B–R R–W Y 11 874 31269 PARKING BRAKE SW P 4 BRAKE FLUID LEVEL WARNING SW B 2 HIGH BEAM INDICATOR LIGHT [COMB. METER] 2 L–R 1F1B4 510 EAIG 1D11 1E7 3F16 3F20 1 9 W–B W–G W–B W–B W–B R–Y W–B C12 7. 5A ECU–B W–B I 9 W–B 1C7 1K5 EA13 1 YY GENERATOR G 2 I 9 W–B 3D12 3D19 BE AD L JUNCTION CONNECTOR BJ 9 , J10A V 1 W–G DAYTIME RUNNING LIGHT RELAY ( MAIN ) D 8 DRL PKB E IND BRK HI H DIM H–LP +B IG CHG– 2003 TOYOTA TACOMA (EWD517U) 106 HEADLIGHT (w/ DAYTIME RUNNING LIGHT) 1. DAYTIME RUNNING LIGHT OPERATION When the engine is started, voltage generated at TERMINAL L of the generator is applied to TERMINAL 9 of the daytime running light relay (Main). If the parking brake lever is pulled up (The parking brake SW on) at this time, the relay is not activated, so the daytime running light system does not operate. If the parking brake lever is then released (The parking brake SW off), a signal is input to TERMINAL 11 of the relay. This activates the relay, so current flows from battery to the HEAD relay (Point side) to TERMINAL 4 of the DIMMER relay to TERMINAL 1 to HEAD (LO LH), (LO RH) fuse to TERMINAL 1 of the headlights to TERMINAL 3 to TERMINAL 1 of the daytime running light relay (Main) to TERMINAL 2 to GROUND. This causes headlights to light up (Headlights light up dimmer than full brightness.). Once the daytime running light system operates and headlights light up, headlights remain on even if the parking brake lever is pulled up (The parking brake SW on). If the engine stalls and the ignition SW remains on, headlights remain lighted up even through current is no longer output from TERMINAL L of the generator. If the ignition SW is then turned off, the headlights go off. If the engine is started with the parking brake lever released (The parking brake SW off), the daytime running light system operates and headlights light up when the engine starts. 2. HEADLIGHT OPERATION When the light control SW is switched to HEAD position, current flows from the DRL fuse to TERMINAL 4 of the daytime running light relay No.4 to TERMINAL 3 to TERMINAL 1 of the diode to TERMINAL 2 to body ECU to TERMINAL 13 of the light control SW to TERMINAL 16 to GROUND, activating the daytime running light relay No.4. Current then flows from the HEAD (LO LH), (LO RH) fuse to TERMINAL 1 of the headlights to TERMINAL 3 to TERMINAL 2 of the daytime running light relay No.4 to TERMINAL 1 to GROUND, causing headlights to light up at normal intensity. When the dimmer SW is switched to HIGH position, the signal from the dimmer SW is input to the daytime running light relay (Main). This activates the relay and current flows from TERMINAL 4 of the DIMMER relay to TERMINAL 2 to TERMINAL 4 of the daytime running light relay (Main), activating the DIMMER relay. This causes current to flow from TERMINAL 4 of the DIMMER relay to TERMINAL 3 to HEAD (HI LH), (HI RH) fuse to TERMINAL 2 of the headlights to TERMINAL 3 to TERMINAL 2 of the daytime running light relay No.4 to TERMINAL 1 to GROUND, causing headlights to light up at high beam. When the dimmer SW is switched to FLASH position, the daytime running light relay (Main) is activated and current flows from TERMINAL 4 of the DIMMER relay to TERMINAL 2. Current from the DRL fuse flows TERMINAL 4 of the daytime running light relay No.4 to TERMINAL 3 to TERMINAL 1 of the diode to TERMINAL 2 to TERMINAL 8 of the dimmer SW to TERMINAL 16 to GROUND, and also flows from the HEAD (HI LH), (HI RH) fuse to TERMINAL 2 of the headlights to TERMINAL 3 to TERMINAL 2 of the daytime running light relay No.4 to TERMINAL 1 to GROUND, causing the high beam to operate. HEAD RELAY 2–1 : Closed with light control SW at HEAD position or dimmer SW at FLASH position Closed with engine running and parking brake lever released DIMMER RELAY 4–3 : Closed with HEAD relay on and dimmer SW at HIGH or FLASH position : PARTS LOCATION Code See Page Code See Page Code See Page B2 30 (5VZ–FE) G2 30 (5VZ–FE) J9 A 31 (5VZ–FE) B2 32 (3RZ–FE, 2RZ–FE) G2 32 (3RZ–FE, 2RZ–FE) J9 A 33 (3RZ–FE, 2RZ–FE) C12 34 H1 30 (5VZ–FE) J10 B 31 (5VZ–FE) C14 34 H1 32 (3RZ–FE, 2RZ–FE) J10 B 33 (3RZ–FE, 2RZ–FE) D8 34 H2 30 (5VZ–FE) P4 35 D9 34 H2 32 (3RZ–FE, 2RZ–FE) D13 34 J1 35 : RELAY BLOCKS Code See Page Relay Blocks (Relay Block Location) 2 21 R/B No.2 (Engine Compartment Left) SYSTEM OUTLINE SERVICE HINTS 2003 TOYOTA TACOMA (EWD517U) 107 ,,, ,,, ,,, : JUNCTION BLOCK AND WIRE HARNESS CONNECTOR Code See Page Junction Block and Wire Harness (Connector Location) 1B 1C 23 Cowl Wire and J/B No.1 (Lower Finish Panel) 1D () 1E 23 Engine Room Main Wire and J/B No.1 (Lower Finish Panel) 1F 23 Cowl Wire and J/B No.1 (Lower Finish Panel) 1K 23 Engine Room Main Wire and J/B No.1 (Lower Finish Panel) 1L 22 Cowl Wire and J/B No.1 (Lower Finish Panel) 3A 3D 24 Cowl Wire and J/B No.3 (Behind the Instrument Panel Left) 3F () : CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS Code See Page Joining Wire Harness and Wire Harness (Connector Location) EA1 40 (5VZ–FE) Engine Room Main Wire and Engine No 2 Wire (Near the Battery)EA1 42 (3RZ–FE, 2RZ–FE) Engine Room Main Wire and Engine No.2 Wire (Near the Battery) IF1 44 Engine Room Main Wire and Cowl Wire (Left Kick Panel) : GROUND POINTS Code See Page Ground Points Location EA 40 (5VZ–FE) Front Left FenderEA 42 (3RZ–FE, 2RZ–FE) Front Left Fender IE 44 Around the Right Edge of the Reinforcement IG 44 Around the Left Edge of the Reinforcement : SPLICE POINTS Code See Page Wire Harness with Splice Points Code See Page Wire Harness with Splice Points E3 40 (5VZ–FE) Engine Room Main Wire I9 44 Cowl Wire E3 42 (3RZ–FE, 2RZ–FE) Engine Room Main Wire . headlights to TERMINAL 3 to TERMINAL 1 of the daytime running light relay (Main) to TERMINAL 2 to GROUND. This causes headlights to light up (Headlights light. L W–G W–G 87 BATTERY DIODE ( DAYTIME RUNNING LIGHT SYSTEM ) D13 DAYTIME RUNNING LIGHT RELAY NO. 4 D 9 HEADLIGHT RH H 2 HEADLIGHT LH H 1 HEAD RELAY C14 COMBINATION