Wiring Diagram SEAT LEON 2004 - Alternator - battery - starter - voltage regulator
Wiring Diagram SEAT LEON 2004 - Glow plugs; terminal 30 voltage supply relay - accelerator position sender - glow plug activation control unit
| F8 | Kick-down switch |
| F60 | Idling speed switch |
| G79 | Accelerator position sender |
| J248 | Diesel direct injection system control unit |
| J370 | Glow plug activation control unit |
| J317 | Terminal 30 voltage supply relay |
| Q6 | Engine glow plug |
| T4nd | 4-pin connector, in engine compartment |
| T6l | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10h | 10-pin connector, blue, in connector protective housing, on left in plenum chamber |
| A104 | Positive connection 2 (15), in dash panel wiring harness |
| * | Wire W for self-diagnosis |
Wiring Diagram SEAT LEON 2004 - Diesel direct injection system control unit - coolant temperature display sender - engine speed sender - intake manifold pressure sender
| G2 | Coolant temperature display sender |
| G28 | Engine speed sender |
| G62 | Coolant temperature sender |
| G71 | Intake manifold pressure sender |
| G72 | Intake manifold temperature sender |
| J248 | Diesel direct injection system control unit |
| J293 | Radiator fan control unit |
| T3d | 3-pin connector, near intake manifold |
| T10d | 10-pin connector, green, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, in left wiring harness |
| 200 | Earth connection (screening), in engine compartment wiring harness |
Wiring Diagram SEAT LEON 2004 - Diesel direct injection system control unit - hall sender - fuel temperature sender - unit injector valve - No. 1 cyl. - unit injector valve - No. 2 cyl.
| E35 | Air conditioning system switch |
| G40 | Hall sender |
| G81 | Fuel temperature sender |
| J248 | Diesel direct injection system control unit |
| J255 | Climatronic control unit |
| J293 | Radiator fan control unit |
| N240 | Unit injector valve, No. 1 cyl. |
| N241 | Unit injector valve, No. 2 cyl. |
| N242 | Unit injector valve, No. 3 cyl. |
| N243 | Unit injector valve, No. 4 cyl. |
| T8x | 8-pin connector, near injection pump |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10d | 10-pin connector, green, in connector protective housing, on left in plenum chamber |
| * | only models with multifunction display |
Wiring Diagram SEAT LEON 2004 - Diesel direct injection system control unit - air mass meter - exhaust gas recirculation valve - harge pressure control solenoid valve
| D | Ignition/starter switch |
| G70 | Air mass meter |
| J104 | ABS control unit with EDL |
| J248 | Diesel direct injection system control unit |
| N18 | Exhaust gas recirculation valve |
| N75 | Charge pressure control solenoid valve |
| N239 | Variable intake manifold flap change-over valve |
| S237 | Fuse on fuse holder |
| T10d | 10-pin connector, green, in connector protective housing, on left in plenum chamber |
| T10y | 10-pin connector, on front of engine |
| T14a | 14-pin connector, in left wiring harness |
| A80 | Connection 1 (X), in dash panel wiring harness |
| D102 | Connection 2, in engine compartment wiring harness |
| * | only models with auxiliary heater |
| ** | only models without auxiliary heater |
Wiring Diagram SEAT LEON 2004 - Diesel direct injection system control unit - cruise control system switch - cruise control system (CCS) SET button - brake light switch - clutch pedal switch
| E45 | Cruise control system switch |
| E227 | Cruise control system (CCS) SET button |
| F | Brake light switch |
| F36 | Clutch pedal switch |
| F63 | Brake pedal switch |
| J248 | Diesel direct injection system control unit |
| S13 | Fuse in relay plate fuse holder |
| T4nc | 4-pin connector, on clutch pedal |
| T10d | 10-pin connector, green, in connector protective housing, on left in plenum chamber |
| T10e | 10-pin connector, black, in connector protective housing, on left in plenum chamber |
| T10s | 10-pin connector, right next to steering column |
| A98 | Positive connection 4 (30), in dash panel wiring harness |
| W1 | Positive connection 1 (54), in rear wiring harness |
Wiring Diagram SEAT LEON 2004 - Diesel direct injection system control unit - low heat output relay - high heat output relay - intake manifold preheating heater element
| J248 | Diesel direct injection system control unit |
| J359 | Low heat output relay |
| J360 | High heat output relay |
| N51 | Intake manifold preheating heater element |
| Q7 | Coolant heating element |
| T6l | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T10y | 10-pin connector, on front of engine |
| |
| 131 | Earth connection 2, in engine compartment wiring harness |
| D50 | Positive connection (30), in engine compartment wiring harness |
| D74 | Connection (86), in engine compartment wiring harness |
| D98 | Connection (glow plugs), in engine compartment wiring harness |
| D111 | Connection 9, in engine compartment wiring harness |
| * | only models with auxiliary heater |
| ** | for models with additional glow plug only |
Wiring Diagram SEAT LEON 2004 - Fuel pump - fuel pump relay - coolant shortage indicator sender - fuel gauge sender
| G | Fuel gauge sender |
| G6 | Fuel system pressurisation pump |
| G32 | Coolant shortage indicator sender |
| G169 | Fuel gauge sender 2 |
| J17 | Fuel pump relay |
| T6l | 6-pin connector, brown, in connector protective housing, on left in plenum chamber |
| T9b | 9-pin connector, on additional relay carrier |
| T10d | 10-pin connector, green, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, in left wiring harness |
| |
| 81 | Earth connection 1, in dash panel wiring harness |
| 269 | Earth connection (sender earth) 1, in dash panel wiring harness |
| A71 | Connection (86), in dash panel wiring harness |
| A100 | Connection 2 (87), in dash panel wiring harness |
| B168 | Connection (86), in interior wiring harness |
| B429 | Connection (EFPR), in main wiring harness |
| * | only for 2V |
Wiring Diagram SEAT LEON 2004 - Control unit with display in dash panel insert - oil pressure switch - speedometer sender - oil level and oil temperature sender
| F1 | Oil pressure switch |
| F4 | Reversing light switch |
| G22 | Speedometer |
| G266 | Oil level and oil temperature sender |
| J285 | Control unit with display in dash panel insert |
| K3 | Oil pressure warning lamp |
| K83 | Exhaust emissions warning lamp |
| S7 | Fuse in relay plate fuse holder |
| T10 | 10-pin connector, orange, in connector protective housing, on left in plenum chamber |
| T14a | 14-pin connector, in left wiring harness |
| |
| 85 | Earth connection 1, in engine compartment wiring harness |
| A20 | Connection (15a), in dash panel wiring harness |
| B163 | Positive connection 1 (15), in interior wiring harness |
| * | only models with extended servicing intervals |
Wiring Diagram SEAT LEON 2004 - Control unit in dash panel insert - fuel gauge - coolant temperature gauge - speedometer - oil pressure warning buzzer
| G1 | Fuel gauge |
| G3 | Coolant temperature gauge |
| G21 | Speedometer |
| H11 | Oil pressure warning buzzer |
| J285 | Control unit with display in dash panel insert |
| K2 | Alternator warning lamp |
| K28 | Coolant temperature and coolant shortage warning lamp |
| K105 | Reserve fuel warning lamp |
| * | Wire W for self-diagnosis |
Wiring Diagram SEAT LEON 2004 - Control unit with display in dash panel insert - multifunction display - multifunction display call-up button - multifunction display memory switch
| E86 | Multifunction display call-up button |
| E109 | Multifunction display memory switch |
| G5 | Rev. counter |
| J119 | Multifunction display |
| J255 | Climatronic control unit |
| J285 | Control unit with display in dash panel insert |
| K29 | Glow period warning lamp |
| T6d | 6-pin connector |
| T12d | 12-pin connector, on Climatronic |
| A27 | Connection (speed signal), in dash panel wiring harness |
| * | only models with multifunction display |
SEAT LEON 2004 Overview of relay
Overview of relay | | |

SEAT LEON 2004 Relay on relay plate
Relay on relay plate | | 1 - | Dual tone horn relay -J4- (53) |
| 2 - | X-contact relief relay -J59- (100) |
| 4 - | Fuel pump relay -J17- (409) |
| - | Glow plug relay -J52- (103) |
| V y Vl - | Automatic intermittent wash and wipe relay -J31- |
| - | with rain sensor, with/without headlight washer system (192) |
| - | without rain sensor, with headlight washer system (389) |
| - | without rain sensor, without headlight washer system (377) |
|
| SEAT LEON 2004 Relay on the 13 position additional relay carrier above the relay plate
Relay on the 13 position additional relay carrier above the relay plate | | 10 - | Fuel pump relay (turbo diesel engine unit injectors) (167) -J17- (up to October 2002) |
| - | Fuel pump relay (TDI-PD) (53) (from November 2002) |
| 11 - | Automatic gearbox relay AG4 -J60- (175) |
| 12 - | Terminal 30 voltage supply relay -J317- (109) |
| 13 - | Radiator fan relay (53) |
|
| | Right-handdrive vehicles: | | 6 - | Telephone switch-over relay | | 7 - | Radiator fan relay -J26- (53) | | 8 - | Terminal 30 voltage supply relay (109) | | 9 - | Automatic gearbox relay AG4 -J60- (175) | | 10 - | Fuel pump relay (turbo diesel engine unit injectors)-J17- (167) (up to October 2002) | | - | Fuel pump relay (TDI-PD) (53) (from November 2002) | | 12 - | Cigarette lighter relay Australia -J193- (53) | | |
|
SEAT LEON 2004 Glow plug activation control unit:
|