Volkswagen Polo 4th generation was produced in 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 and 2009 with sedan and hatchback bodies. In 2005, the car was updated and an additional model made in the off-road style Cross Polo was introduced . In this publication, we will show where all the electronic control units are located in the Volkswagen Polo 4. We will separately highlight the purpose of fuses and relays with diagrams of the blocks in which they are located.
General arrangement of control units
Scheme
Table with description of elements
| 1 | Air conditioning control unit – in the heater control panel |
| 2 | Air conditioner/heater fan motor control unit (with automatic temperature control) – fan unit |
| 3 | Antenna signal amplifier (audio system) – in the audio system antenna |
| 4 | Antenna signal amplifier (navigation system) – in the audio system antenna |
| 5 | Side impact sensor, driver’s side under the front seat |
| 6 | Side sensor, passenger side – under the front seat |
| 7 | Side impact sensor, left rear (left curtain airbag) – luggage compartment, behind left trim panel |
| 8 | Side impact sensor, right rear (right curtain airbag) – luggage compartment, behind right trim panel |
| 9 | Anti-theft system control unit – in the multifunctional control unit 2 |
| 10 | Anti-theft system sound signal – behind the rear left wheel arch trim |
| 11 | Volume change sensor (anti-theft system) – front interior light |
| 12 | Rechargeable battery |
| 13 | Central locking control unit – in multifunction control unit 2 |
| 14 | Diagnostic Connector (DLC) |
| 15 | Diagnostic unit – in the multifunctional control unit 1 |
| 16 | Door function control unit, front left (central locking/door mirror/power window) |
| 17 | Door function control unit, front right (central locking/door mirror/power window) |
| 18 | Door function control unit, rear left (central locking/power windows) |
| 19 | Door function control unit, rear right (central locking/power windows) |
| 20 | Cooling system fan motor control unit – with air conditioning – AXU |
| 21 | Fuse/relay block instrument panel 1 |
| 22 | Fuse/relay block instrument panel 2 |
| 23 | Fuse/relay block, engine compartment above battery |
| 24 | Additional fuse (5A/7.5A/10A) – at the rear of the audio unit/navigation control unit |
| 25 | Heater fan motor resistor (manual temperature control) – fan unit |
| 26 | Heater fan motor resistor (automatic temperature control) – in the air conditioner/heater fan motor control unit |
| 27 | Heater control unit – in the heater control panel – without air conditioning |
| 28 | Horn(s) — behind the front bumper |
| 29 | Immobilizer control unit – in the instrument cluster |
| 30 | Immobilizer ring antenna – near the ignition switch |
| 31 | Turn signal/hazard alarm relay – in multifunction control unit 1 |
| 32 | Instrument cluster control unit, digital multifunction display – on the instrument cluster – functions: Immobilizer, warning devices and indicators |
| 33 | Warning buzzer for lights left on – in the instrument cluster |
| 34 | Multifunction control unit 1 – under the fuse box / relay 2 of the dashboard – functions: Cruise control system, electric drive / heated rear-view mirrors on the doors, starting relay (fuel system), rear window heater, horn, turn signals, hazard warning lights, interior lights, rear window wiper, reversing light (automatic transmission), windshield washers, windshield wipers |
| 35 | Multifunctional control unit 2-functions: Anti-theft system, central locking, electric drive and heater of rear-view mirrors on the doors, electric drive of power windows |
| 36 | Navigation system antenna – in the audio system antenna |
| 37 | Navigation system control unit – in the navigation system/radio control panel |
| 38 | Outside air temperature sensor behind the front bumper |
| 39 | Power steering control unit |
| 40 | Rain sensor – in the interior rearview mirror |
| 41 | Driver’s seat heating control unit under the front seat |
| 42 | Passenger seat heating control unit – under the front seat |
| 43 | SRS system control unit – behind the center console |
| 44 | Sunroof control unit – behind the interior light bulb |
| 45 | Phone antenna – in the audio system antenna |
| 46 | Telephone interface control unit – front right space |
| 47 | Electronic gearbox control unit |
| 48 | Vehicle speed sensor – except 11/02 – > without ABS – gearbox |
Fuse block
The fuse panel is located in the passenger compartment, at the end of the instrument panel on the driver’s side and is covered by a protective cover. Check the current fuse designation and numbers on the inside of the cover.
Purpose of fuses
| 1 | 10A Wiper, rear window washer |
| 2 | 5A Instrument cluster backlight rheostat, license plate backlight lamps |
| 3 | 5A Rear fog lights |
| 4 | 5A Brake light switch (brake pedal position sensor), cruise control system, engine management system |
| 5 | 5A Engine management, exhaust gas recirculation |
| 6 | 5A Headlight leveling |
| 7 | 5A Engine management, power steering |
| 8 | 5A Heated door mirrors |
| 9 | 10A Motor control |
| 10 | 5A S-contact |
| 11 | 5A Electric drive for heated rear-view mirrors |
| 12 | 5A Front right side marker lamps, rear right side marker lamps |
| 13 | 5A Front left side marker lamps, rear left side marker lamps |
| 14 | 10A Engine management system, intake manifold heater |
| 15 | 10A Automatic transmission |
| 16 | 10A Windshield wiper, washer |
| 17 | 5A Engine control |
| 18 | 5A Air conditioning system, air recirculation system (air conditioner/heater), anti-theft system, auto-dimming interior rearview mirror, cooling system fan motor control unit, instrument cluster, navigation system |
| 19 | 10A Windshield washer nozzle heaters, reversing lights |
| 20 | 5A Instrument cluster |
| 21 | 10A Right headlight-high beam |
| 22 | 10A Left headlight – high beam |
| 23 | 10A Anti-lock braking system, stability control |
| 24 | 10A Multifunction control unit 1 |
| 25 | 10A Motor control |
| 26 | 10A Stop signals |
| 27 | 5A Anti-lock braking system (with ESP), instrument cluster |
| 28 | 10A Interior lights |
| 29 | 5A Air conditioning system, diagnostic connector (DLC), telephone |
| 30 | 5A Multifunction control unit 1, automatic transmission selector lock system, rain sensor (windshield wiper) |
| 31 | 25A Front left door window motor |
| 32 | 15A Seat heater |
| 33 | 15A Anti-theft alarm sound |
| 34 | 15A Accessory power connector |
| 35 | 20A Hatch |
| 36 | 25A Air conditioner/heater fan motor |
| 37 | 15A20A Ignition coil(s), ignition system switch(es) |
| 38 | 25A Rear left door power window motor |
| 39 | 25A Front right door power window motor |
| 40 | 10A/30A Motor control |
| 41 | 15A Fuel pump that primes the fuel pump – petrol/TDI |
| 42 | 20A Engine control – AXU |
| 43 | 15A Right headlight – low beam, headlight range control |
| 44 | 15A Fog lights |
| 45 | 15A Engine Management – AUB |
| 46 | 20A Windshield wiper, washer |
| 47 | 20A Rear window heater (^02/04) |
| 48 | 15A Turn signals, hazard warning lights |
| 49 | 15A Cigarette lighter |
| 50 | 15A Multifunction control unit 2, anti-theft system, central locking |
| 51 | 15A Audio system, navigation system |
| 52 | 20A Horn, wiper, windshield washer |
| 53 | 25A Rear right door power window motor |
| 54 | 15A Left headlight – low beam, headlight range control |
Fuse 49 at 15A is responsible for the cigarette lighter.
Relay block
The relay block is located behind the dashboard trim on the driver’s side. The Polo has a single relay block with the same type of sockets.
Scheme
Transcript
| 1 | Reserve |
| 2 | Relay in the Motronic system power supply circuit |
| 3 | (100) Glow plug relay |
| 4 | (53) Fuel pump relay (TDI) |
| 5 | (449) Relay for switching on the door position lamp, door opening illumination lamps |
| 6 | (53) Headlight washer pump relay |
| 7 | (126) Starter lockout relay |
| 8 | (53) Auxiliary heater relay 1, low power |
| 9 | (100) Auxiliary heater relay 2, high output (diesel) |
| 10 | (53/429) Engine control system relay (petrol, except AXU) |
| 11 | (18) Auxiliary ignition circuit relay, Terminal X unloader relay |
| 12 | (404) Starter relay (fuel system) (petrol, except AXU) |
| 13 | (167) Fuel pump relay (petrol engine, except AXU) |
| 14 | Fuse block in the autonomous heater circuit |
| 15 | (109) Engine control system relay (diesel) |
Some fuses, for example, an additional 40A heater, can also be mounted in this block.
Main fuse block
It is located on the battery cover. The number of fuses included in it depends on the specific vehicle configuration. The block holders can accommodate no more than 6 flat fuses and 10 blade-type fuses. The connection to the positive terminal is made using a wire with a terminal tip and a screw. The fuses protect individual circuits of the on-board network from loading directly at the battery output.
Description
| 1 | 110A Generator |
| 2 | 110 Interior, ignition switch |
| 3 | 50A Power steering |
| 4 | 50A Engine control relay (AXU), exhaust air pump |
| 5 | 40A Cooling system fan motor |
| 6 | 40A Anti-lock braking system (ABS) |
| 7 | 40A Anti-lock braking system (ABS) |
| 8 | 30A Cooling system fan motor |
| 9 | Reserve |
| 10 | 5A Multifunction control unit 1 |
| 11 | 5A Air conditioning system, cooling system fan motor control unit |
| 12 | Reserve |
| 13 | 5A Automatic transmission |
| 14 | Reserve |
| 15 | Reserve |
| 16 | Reserve |