Contents Wiring diagrams Section: Electrical Component Locations All sections

Electrical Component Locator: Other Audi A4 B5 facelift

BUZZERS, RELAYS & TIMERS

ComponentComponent Location
A/C Clutch RelayOn 13-pin relay carrier, position No. 3. (Схема №7)
Coolant Fan Control (FC) RelayOn 8-pin relay carrier, position No. 3. (Схема №6)
Daytime Running Lights Switch-On RelayOn 13-pin relay carrier, position No. 8. (Схема №7)
Driving Light RelayOn 13-pin relay carrier, position No. 9. (Схема №7)
Dual Horn RelayOn micro central electric, position No. 1. (Схема №5)
Foglight RelayOn 13-pin relay carrier, position No. 7. (Схема №7)
Fuel Pump RelayOn micro central electric, position No. 4. (Схема №5)
Load Reduction RelayOn micro central electric, position No. 2. (Схема №5)
Motronic Engine Control Module (ECM) Power Supply RelayOn 3-pin relay carrier, position No. 3. (Схема №4)
Park/Neutral Position RelayOn 13-pin relay carrier, position No. 13. (Схема №7)
Power Window/Sun Roof Control Module RelayOn 8-pin relay carrier, position No. 4. (Схема №6)
Second Speed Coolant Fan Control (FC) RelayOn 8-pin relay carrier, position No. 2. (Схема №6)
Secondary Air Injection (AIR) RelayOn 3-pin relay carrier, position No. 2. (Схема №4)
Selector Lever Light RelayOn 13-pin relay carrier, position No. 6. (Схема №7)
Wiper/Washer Intermittent Relay (2)On micro central electric, positions No. 5 & 6. (Схема №5)

BUZZERS, RELAYS & TIMERS

CIRCUIT PROTECTION DEVICES

ComponentComponent Location
Fuse PanelOn left end of dash. (Схема №8)
Micro Central ElectricBehind left side of dash. (Схема №8)
3-Pin Relay CarrierNear brake booster, in ECM case.
8-Pin Relay CarrierBelow left end of dash. (Схема №8)
13-Pin Relay CarrierBehind left end of dash, above micro central electric. (Схема №8)

CIRCUIT PROTECTION DEVICES

CONTROL UNITS

ComponentComponent Location
ABS Control ModuleIn left front corner of engine compartment.
Air Bag Control ModuleIn center console. (Схема №8)
Antenna Selection Control ModuleIn trunk, on CD changer bracket.
Central Locking/Interior Light Delay/Anti-Theft Alarm Control ModuleOn bottom right of luggage compartment. (Схема №8)
Cruise Control, Control ModuleBehind right side of dash. (Схема №8)
Door Warning Lights Control ModuleOn 8-pin relay carrier, position 5. (Схема №6)
Fresh Air Blower Control ModuleBehind right side of dash.
Headlight Leveling Control ModuleUnder right side of rear seat.
Heated Door Lock Control Module (Left)Upper part of left front door. (Схема №8)
Motronic Engine Control Module (ECM)Near brake booster, in protective case. (Схема №8)
Power Sunroof Control ModuleAt center of windshield header, above headliner.
Radiator Fan Control ModuleIn lower right front corner of engine compartment, on frame rail.
Rear Light Control ModuleOn 13-pin relay carrier, position No. 4 & No. 5. (Схема №7)
Throttle Valve Control Module (1.8L)On left side of engine, on intake manifold. (Схема №1)
Throttle Valve Control Module (2.7L)On front of engine, on intake manifold. (Схема №2)
Throttle Valve Control Module (2.8L)On rear of engine, on intake manifold. (Схема №3)
Transmission Control Module (TCM)Under carpet, forward of passenger's seat. (Схема №8)
Ultra-Sound Sensor Control ModuleBelow center of rear seat. (Схема №8)

CONTROL UNITS

MOTORS

ComponentComponent Location
Airflow Flap MotorBehind right side of dash, near blower motor.
Blower MotorBehind right side of dash, on HVAC housing.
Central Air Flap MotorBehind lower center of dash, near transmission tunnel.
Central Locking MotorBelow center of rear seat.
Cruise Control Vacuum PumpIn left front corner of engine compartment, near power steering reservoir.
Footwell/Defroster Flap MotorBehind lower right center of dash, near transmission tunnel.
Fuel PumpIn fuel tank.
Headlight Washer PumpIn left front corner of engine compartment.
Leak Detection PumpIn the driver side left rear wheelhouse, above plastic liner.
Rear Windshield Wiper MotorOn center of rear hatch, behind trim panel.
Secondary Air Injection (AIR) Pump Motor (2.8L)In lower right front corner of engine compartment.
Temperature Regulator Flap MotorBehind lower right center of dash, near transmission tunnel.
Windshield Washer PumpIn left front corner of engine compartment.

MOTORS

SENDING UNITS & SENSORS

ComponentComponent Location
ABS Wheel Speed Sensor (4)On respective hub/spindle assembly.
Accelerator Pedal Position Sender (2.7L)Above accelerator pedal, on bracket.
Anti-Theft Warning System Ultra-Sound Sensor (Left)Behind top of left "B" pillar trim panel.
Anti-Theft Warning System Ultra-Sound Sensor (Right)Behind top of right "B" pillar trim panel.
Back Pressure Flap Motor Position SensorBehind right side of dash, near base of "A" pillar.
Barometric Pressure SensorNear brake booster, in ECM protective case.
Camshaft Position (CMP) Sensor (1.8L)On front of cylinder head, behind timing belt cover. (Схема №1)
Camshaft Position (CMP) Sensor Bank 2 (2.7L)On rear of left cylinder head. (Схема №2)
Camshaft Position (CMP) Sensor Bank 2 (2.8L)On rear of left cylinder head. (Схема №3)
Camshaft Position (CMP) Sensor 2 (2.7L)On front of right cylinder head.
Camshaft Position (CMP) Sensor 2 (2.8L)On front of right cylinder head. (Схема №3)
Center Outlet Temperature SenderBehind lower center of dash, on HVAC unit.
Central Flap Motor Position SensorBehind lower right center of dash, on HVAC unit.
Charge Air Pressure Sensor (2.7L)On center of intake manifold.
Crash Sensor For Side Air Bag (Left)Beneath left front seat, on frame rail.
Crash Sensor For Side Air Bag (Right)Beneath right front seat, on frame rail.
Engine Coolant Temperature (ECT) Sensor (1.8L)At rear of cylinder head, on coolant flange. (Схема №1)
Engine Coolant Temperature (ECT) Sensor (2.7L)At rear of right cylinder head, on coolant pipe. (Схема №2)
Engine Coolant Temperature (ECT) Sensor (2.8L)At rear of right cylinder head, on coolant pipe. (Схема №3)
Engine Oil Temperature Sensor (1.8L)On left side of engine, on oil filter housing. (Схема №1)
Engine Oil Temperature Sensor (2.7L)On lower left front of engine.
Engine Oil Temperature Sensor (2.8L)On lower left front of engine.
Engine Speed (RPM) Sensor (1.8L)On left side of engine, near oil filter housing.
Engine Speed (RPM) Sensor (2.7L)On left side of transmission bellhousing.
Engine Speed (RPM) Sensor (2.8L)On left side of transmission bellhousing.
Exhaust Temperature Sender 1 (2.7L)In outlet side of right turbocharger housing.
Exhaust Temperature Sender 2 (2.7L)In outlet side of left turbocharger housing.
Floor Outlet Temperature SenderBehind lower left center of dash, on HVAC unit.
Footwell/Defrost Flap Motor Position SensorBehind lower center of dash, above accelerator pedal.
Fresh Air Intake Duct SensorBehind right side of dash, near blower motor.
Fuel Gauge SenderIn fuel tank, integrated with fuel pump assembly.
Headlight Level Sensor (Front)Attached to right front lower suspension arm.
Headlight Level Sensor (Rear)Attached to right rear lower suspension arm.
Heated Oxygen Sensor (HO2S) (1.8L)On right side of engine, on exhaust manifold. (Схема №1)
Heated Oxygen Sensor (HO2S) (2.7L)On exhaust manifold, behind right cylinder head.
Heated Oxygen Sensor (HO2S) (2.8L)Behind right cylinder head, on exhaust manifold.
Heated Oxygen Sensor (HO2S) 2 (2.7L)On exhaust manifold, behind left cylinder head.
Heated Oxygen Sensor (HO2S) 2 (2.8L)Behind left cylinder head, on exhaust manifold.
Intake Air Temperature (IAT) Sensor (1.8L)On intake manifold, near throttle valve control module. (Схема №1)
Intake Air Temperature (IAT) Sensor (2.7L)On bottom of intake manifold, behind throttle valve control module. (Схема №2)
Intake Air Temperature (IAT) Sensor (2.8L)On rear of intake manifold, in intake duct.
Knock Sensor (KS) 1 (1.8L)On left front of engine block.
Knock Sensor (KS) 1 (2.7L)On right side of engine block, under intake manifold.
Knock Sensor (KS) 1 (2.8L)On right side of engine block, under intake manifold.
Knock Sensor (KS) 2 (1.8L)On left rear of engine block.
Knock Sensor (KS) 2 (2.7L)On left side of engine block, under intake manifold.
Knock Sensor (KS) 2 (2.8L)On left side of engine block, under intake manifold.
Mass Airflow (MAF) Sensor (1.8L)Inside of air cleaner housing.
Mass Airflow (MAF) Sensor (2.7L)Attached to air cleaner housing. (Схема №2)
Mass Airflow (MAF) Sensor (2.8L)Attached to air cleaner housing. (Схема №3)
Outside Air Temperature SensorBehind center of lower front grille.
Oxygen Sensor Behind TWC (1.8L)Rearward of cylinder head, in engine compartment.
Oxygen Sensor Behind TWC (2.7L) (2)Downstream of respective TWC.
Oxygen Sensor Behind TWC (2.8L) (2)Downstream of respective TWC.
Sunlight Photo SensorInside defroster grille, on center of dashboard.
Temperature Flap Motor Position SensorBehind lower right center of dash, near transmission tunnel.
Throttle Position Sender (2.7L)Above accelerator pedal, on bracket.
Transmission Vehicle Speed Sensor (VSS)On left side of transmission, near axle flange.

SENDING UNITS & SENSORS

SOLENOIDS & SOLENOID VALVES

ComponentComponent Location
Camshaft Adjustment Valve 1On rear of right cylinder head.
Camshaft Adjustment Valve 2On front of left cylinder head.
Evaporative Emissions (EVAP) Canister Purge Regulator Valve (1.8L)On top of air cleaner housing. (Схема №1)
Evaporative Emissions (EVAP) Canister Purge Regulator Valve (2.7L)On upper right side of engine, near intake duct. (Схема №2)
Evaporative Emissions (EVAP) Canister Purge Regulator Valve (2.8L)On top of air cleaner housing.
Intake Manifold Tuning (IMT) Valve Changeover Valve (2.8L)On rear of intake manifold. (Схема №3)
Secondary Air Injection (AIR) Solenoid Valve (2.8L)On rear of intake manifold, near air intake duct. (Схема №3)
Shift Lock SolenoidAt base of gear selector lever.
Turbocharger Recirculating Valve (2.7L)On top of engine, left of intake duct. (Схема №2)
Wastegate By-Pass Regulator Valve (1.8L)In right front corner of engine compartment, attached to intake duct.
Wastegate By-Pass Regulator Valve (2.7L)On upper right side of engine, near intake duct. (Схема №2)

SOLENOIDS & SOLENOID VALVES

SWITCHES

ComponentComponent Location
A/C Pressure SwitchBelow passenger side headlight.
After-Run Coolant Thermal Switch (2.7L)On rear of left cylinder head, in coolant piping.
Brake Light SwitchAbove brake pedal, on bracket.
Clutch Pedal Position SwitchAbove clutch pedal, on bracket.
Clutch Vacuum Vent Valve SwitchAbove clutch pedal, on bracket.
Coolant Fan Control (FC) Thermal SwitchOn lower radiator hose.
Engine Coolant Level (ECL) Warning SwitchOn coolant reservoir.
Hood Alarm SwitchIntegral with hood latch assembly.
Kickdown Switch (2.8L)On left center of firewall, integral with throttle cable. (Схема №3)
Multifunction Transmission Range (TR) SwitchOn left side of transmission, behind mounting bracket.
Oil Pressure Switch (1.8L)On lower left side of engine, on oil filter housing.
Oil Pressure Switch (2.7L)On lower left front of engine, on oil pan extension.
Oil Pressure Switch (2.8L)On lower left front of engine, on oil pan extension.
Trunk Lock Alarm SwitchIntegral with trunk latch assembly.
Vacuum Vent Valve Brake SwitchIntegral with brake light switch.

SWITCHES

MISCELLANEOUS

ComponentComponent Location
Alarm HornIn rear of luggage compartment, behind trim.
Coolant Fan Control (FC) Series ResistanceOn bottom of left front frame rail, in engine compartment.
Data Link Connector (DLC)Under left side of dash.
Front Seat Belt Tensioner Ignitor (Left)At bottom of left "B" pillar, behind trim panel.
Front Seat Belt Tensioner Ignitor (Right)At bottom of right "B" pillar, behind trim panel.
Head-Level Air Bag Ignitor (Left)On left "C" pillar, behind trim panel.
Head-Level Air Bag Ignitor (Right)On right "C" pillar, behind trim panel.
Ignition Coil (4) (1.8L)On top of cylinder head, beneath decorative cover.
Ignition Coil (6) (2.7L)On top of respective cylinder head, beneath decorative cover.
Ignition Coil (2.8L)On top front of engine. (Схема №3)
Left Connector StationUnder bottom of left "A" pillar trim. (Схема №8)
Power Output Stage (1.8L)On top of air cleaner housing. (Схема №1)
Power Output Stage (2.7L)On top of air cleaner housing. (Схема №2)
Power Output Stage (2.8L)Integral with ignition coil.
Power Output Stage 2 (2.7L)On top of air cleaner housing, with brown connectors. (Схема №2)
Rear Seat Belt Tensioner Ignitor (Center)Behind center rear seat back.
Rear Seat Belt Tensioner Ignitor (Left)Behind left rear seat back, behind trim panel.
Rear Seat Belt Tensioner Ignitor (Right)Behind right rear seat back, behind trim panel.
Right Connector StationUnder bottom of right "A" pillar trim. (Схема №8)

MISCELLANEOUS

CONNECTORS

ComponentComponent Location
T6 (Yellow, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6A (Red, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6B (Yellow, 6 Pin)Under bottom of left "A" pillar, on connector station.
T6C (Red, 6 Pin)Under bottom of left "A" pillar, on connector station.
T6D (Brown, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6E (Blue, 6 Pin)Under bottom of left "A" pillar, on connector station.
T6F (Orange, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6G (Gray, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6J (Red, 6 Pin)Under bottom of left "A" pillar, on connector station.
T6O (White, 6 Pin)Under bottom of right "A" pillar, on connector station.
T6Q (Orange, 6 Pin)Under bottom of left "A" pillar, on connector station.
T6Z (Red, 6 Pin)In E-box, at left rear of engine compartment.
T8A (Black, 8 Pin)In E-box, at left rear of engine compartment.
T10 (Brown, 10 Pin)In E-box, at left rear of engine compartment.
T10A (Brown, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10B (Orange, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10C (Violet, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10F (Black, 10 Pin)Under bottom of right "A" pillar, on connector station.
T10G (Brown, 10 Pin)Under bottom of right "A" pillar, on connector station.
T10H (Brown, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10I (Black, 10 Pin)Below rear of center console.
T10J (Green, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10K (Red, 10 Pin)At left "B" pillar.
T10M (Black, 10 Pin)In E-box, at left rear of engine compartment.
T10N (Red, 10 Pin)Under bottom of right "A" pillar, on connector station.
T10O (Red, 10 Pin)On right "B" pillar.
T10Q (Blue, 10 Pin)Under bottom of left "A" pillar, on connector station.
T10V (Brown, 10 Pin)Under bottom of right "A" pillar, on connector station.
T10X (Blue, 10 Pin)Under bottom of right "A" pillar, on connector station.
T10Y (Blue, 10 Pin)In E-box, at left rear of engine compartment.
T10Z (Yellow, 10 Pin)In E-box, at left rear of engine compartment.

CONNECTORS

GROUNDS

ComponentComponent Location
G3On right front of engine.
G12At left rear of engine compartment. (Схема №8)
G18On top front of engine.
G32Above left kick panel. (Схема №8)
G43Above right kick panel. (Схема №8)

GROUNDS