Electric Coolant Fans — Audi TT 8N (1998-2003)

1.8L Turbo

Engine number (engine code and serial number) can be found at front, on machined surface, next to joint between engine and transmission. (Scheme 1) There is also a sticker, on cylinder head cover showing engine code and serial number. Engine code is also included on vehicle data sticker.

Scheme 1

Scheme 1: 1.8L Turbo

3.2L V6 Turbo

Engine number (engine code and serial number) can be found at front, on machined surface, next to joint between engine and transmission. (Scheme 2) There is also a sticker on cylinder head cover, showing engine code and serial number. Engine code is also included on vehicle data sticker.

Scheme 2

Scheme 2: 3.2L V6 Turbo

A/C PRESSURE SWITCH (F129)

A/C pressure switch is a combination switch (two switching components) that protects refrigerant circuit components from malfunctioning due to excessive or insufficient refrigerant system pressures. Switch part between terminals 1 and 2 switches off the A/C clutch when the system pressure is too high or when there is not enough refrigerant in the system. Switch part between terminals 3 and 4 switches coolant fan to second fan speed when system pressures increase.

A/C HIGH PRESSURE SENSOR (F65)

A/C High Pressure Sensor sends a digital signal to A/C Control Module. The A/C High Pressure Sensor needs to sense a pressure between 26 psi (1.8 bar) 464 psi (32 bar) for the A/C system to turn on. The Coolant Fan Control Module (J293) regulates coolant fan speed.

1.8L Turbo With A/C Pressure Switch (F129)

Note. Early production 1.8L Turbo models have the A/C Pressure Switch (F129).

After-Run Coolant Pump (V51), Coolant Fans No.1 (V7) and No. 2 (V177) are controlled by the Coolant Fan Control Module (J293). Coolant Fan Control Modules utilizes input from Coolant Fan Control Thermo Switch and A/C Control Head (E87).

1.8L Turbo & 3.2L V6 Turbo With A/C High Pressure Sensor (F65)

After-Run Coolant Pump (V51), Coolant Fans No.1 (V7) and No. 2 (V177) are controlled by the Coolant Fan Control Module (J293). Coolant Fan Control Module (J293) utilizes input from Coolant Fan Control Thermo Switch, After-Run Coolant Pump Thermo Switch (F95), A/C Control Head (E87) and ECM (J220).

Both fans are actuated with infinitely variable control by the Coolant Fan Control Module (J293).

1.8L Turbo & 3.2L With A/C High Pressure Sensor (F65)

Both fans are actuated with infinitely variable control by the Coolant Fan Control Module (J293), with ECM (J220) input.

Coolant Fan Control Module (J293) controls Coolant Fan No. 1 (V7) and No. 2 (V177) and After-Run Coolant Pump (V51). Coolant Fan Control Modules utilizes input from Coolant Fan Control Thermo Switch and A/C Control Head (E87).

Coolant Fan Control Module (J293) controls Coolant Fans No.1 (V7) and No. 2 (V177) and After-Run Coolant Pump (V51). Coolant Fan Control Module (J293) utilizes input from Coolant Fan Control Thermo Switch, After-Run Coolant Pump Thermo Switch (F95), A/C Control Head (E87) and ECM (J220).

1.8L Turbo & 3.2L V6 Turbo

Coolant Fan Control Thermo Switch is a 2-stage thermo switch. At two independently preset temperatures, (Coolant Fan Thermo Switch specific), the Coolant Fan Thermo Switch first stage signal is completed and a B+ circuit is brings power to the Coolant Fan Control Module (J293), (stage 1 input signal). The Coolant Fan Thermo Switch second stage B+ signal is completed at a higher preset temperature and a B+ circuit is brings power to the Coolant Fan Control Module (J293), stage 2 input signal. Both fans are actuated with infinitely variable control by the Coolant Fan Control Module (J293).

COMPONENT LOCATIONS

Component		Location
A/C High Pressure Sensor (F65), All Models		Engine Compartment, Right Side, Below Plenum. (Scheme 3)
A/C Pressure Switch (F129), Early 1.8L Turbo		Engine Compartment, Right Side, Below Plenum. (Scheme 3)
After Run Coolant Pump, All Models		On Radiator Bracket, Near Cooling fan, Front Of Engine Compartment. (Scheme 4)
Climatronic (Auto A/C) Control Module (E87), All Models		Integrated with A/C Control Panel
Coolant Fan Control Module (J293), All Models		Front Of Engine Compartment, Upper Left, Next To Radiator. (Scheme 5)
Coolant Fan Ground Point, All Models		In Engine Compartment, Left Side, Under Battery Tray
Coolant Fan Thermo Switch, All Models		In Radiator, Lower Left Corner. (Scheme 6)
Fuse Locations
Low Amp Fuses, All Models		Passenger Compartment, Left End Of Dashboard. (Scheme 8)(1).
High Amp Fuses, All Models		Main Fuse Box, Battery. (Scheme 9)(2).
(1) Fuse locations on Passenger Compartment Fuse Box, for Coolant Fan Control Module (J293). All models: Fuse position is No. 5 (7.5A) and 16 (10A). (2) Fuse locations on Main Fuse Box (Battery), for Coolant Fan Control Module (J293). All models: Fuse position is No. 133 (30A) and 164 (30A).

(1)	Fuse locations on Passenger Compartment Fuse Box, for Coolant Fan Control Module (J293). All models: Fuse position is No. 5 (7.5A) and 16 (10A).

(2)	Fuse locations on Main Fuse Box (Battery), for Coolant Fan Control Module (J293). All models: Fuse position is No. 133 (30A) and 164 (30A).

COMPONENT LOCATIONS

Note. A/C Pressure Switch (F129) is used on early 1.8L Turbo models.

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

SYSTEM TESTS

System testing information is not available from manufacturer. To assist in circuit diagnosis, see WIRING DIAGRAMS . Ensure all fuses are okay before proceeding with any testing. If a fuse is blown, check for a short circuit and repair before replacing fuse.

A/C HIGH PRESSURE SENSOR (G65)

The 3-wire sensor pin values are as follows

Pin 1: Ground. (Scheme 10)
Pin 2: Duty Cycle signal to A/C Control Head (E87). (Scheme 10)and «A/C HIGH PRESSURE SENSOR SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/cooling-fan/#electric-coolant-fans) table.
Pin 3: Power when ignition is on (15+). (Scheme 10)

Scheme 10

Duty cycle reading can be used to diagnose A/C high pressure sensor. Turn ignition on, with engine off. See A/C HIGH PRESSURE SENSOR SPECIFICATIONS table.

Duty Cycle	Possible Cause	Corrective Action
12 % to 87.5%	Sensor OK	None. Sensor reading is normal.
88%	Faulty Sensor	Replace Sensor
11%	Low Refrigerant	Recharge A/C System
11%	Faulty Sensor	(1) Replace Sensor
(1) Ensure refrigerant system is fully charged before assuming sensor is faulty.

(1)	Ensure refrigerant system is fully charged before assuming sensor is faulty.

A/C HIGH PRESSURE SENSOR SPECIFICATIONS

The high/low pressure switch (located between terminals 1 and 2) disengages A/C clutch (via A/C control head) when there are excessively high or low refrigerant system pressures. The high pressure switch (between terminals 3 and 4) switches coolant fan(s) V7 to speed 2.

Switch terminal Nos. 3 and 4 control coolant fan operation by the coolant fan control module. Fan speed increases to second speed when system pressure increases. Switch closes above 232 psi (16 bar), and opens again below 181 psi (12.5 bar).

Scheme 11

Scheme 11: 1.8L Turbo & 3.2L V6 Turbo

COOLANT FAN CONTROL THERMO SWITCH

No information is available from the manufacturer.

COOLANT FAN CONTROL MODULE

No information is available from the manufacturer.

1.8L Turbo (Engine Codes AMU & BEA)

Note. After-run coolant pump is located on the fan cowl to the right of the radiator fan. (Scheme 4)and (Scheme 12).

Switch on ignition. After-run coolant pump (V51) should start running (pump can be felt and heard). (Scheme 12) If pump does not run, check fuse and wiring according to wiring diagram. If the fuse is OK and there is no open circuit in the wiring: Replace after-run coolant pump. (Scheme 12)

Scheme 12

Scheme 12: 1.8L Turbo (Engine Codes AMU & BEA)

AFTER-RUN COOLANT PUMP

WARNING

Cover cap of expansion tank with rag and open carefully, hot steam and hot coolant may escape when opening.

Scheme 13

Scheme 13: Removal (3.2L V6 Turbo)

Scheme 14

Scheme 15

Open filler cap on coolant expansion tank. Remove fasteners 1-3 and center sound insulation. (Scheme 13) Place drip tray VAG 1306 under engine. Turn drain plug (arrow) on radiator counterclockwise. (Scheme 14) If necessary install a drain hose to connection.
Remove lower coolant hose at After-run coolant pump and drain remaining coolant. Disconnect electrical connector (1). (Scheme 15) Disconnect coolant hose (2). (Scheme 15) Pull After-run coolant pump downward out of rubber retainers. If necessary, spray with silicone-free lubricant.

Installation (3.2L V6 Turbo)

Installation is performed in the reverse order. Fill cooling system. See COOLING SYSTEM SPECIFICATIONS & DRIVE BELT ROUTING .

Scheme 16

Scheme 16: Removal

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Cover cap of expansion tank with rag and open carefully, hot steam and hot coolant may escape when opening. Open filler cap on coolant expansion tank. Remove fasteners (1) at lock carrier by pressing in pin 2 about 4 mm (do not push in completely). (Scheme 16)
Pull fastener out upward. Remove covers (left side, 1 and 2) at lock carrier and above main fuse box (arrows). (Scheme 17)
Remove covers (right side, 1 and 2) at lock carrier and above coolant expansion tank (arrows). (Scheme 18)
Remove upper securing bolts (upper arrows) for radiator cowl. (Scheme 19)
Release tension of poly V-belt by screwing an M8 x 40 bolt (arrow) into threaded bore on tensioning element. (Scheme 20)
Disconnect secondary air hose at position marked with an arrow. (Scheme 21) Move secondary air hose clear.
Remove fasteners 1-3 and remove sound insulation. (Scheme 13) Remove left sound insulation (arrows). (Scheme 22)
Remove right sound insulation (arrows). (Scheme 23) Remove cross piece (arrows). (Scheme 24)
Remove power steering pump pulley (counterhold with mandrel). Remove bolts (arrows) and remove power steering pump from bracket. (Scheme 25) Hang power steering pump on lock carrier with hydraulic hoses (1 and 2) attached. (Scheme 25)
Disconnect electrical connector (1) at Secondary Air Injection (AIR) pump motor. (Scheme 26) Move wiring clear. Remove bolt (2) for coolant hose bracket. Remove bolt (3) for secondary air pump air filter. (Scheme 26)
Remove bolts (1 and 2) and remove secondary air pump with bracket A. (Scheme 27)
Disconnect electrical connectors (1) for coolant fans at bottom of radiator cowl. (Scheme 28) Unscrew lower securing bolts (lower arrows) for radiator cowl. (Scheme 28)
Disconnect electrical connector (1). (Scheme 29) Move wiring clear. Remove nuts (arrows) and remove fans.

Scheme 29

Scheme 29: Installation

Installation is performed in the reverse order. Reinstalling the poly V-belt in the opposite direction can cause breakage. Poly V-belt is self-adjusting. underneath.
Ensure the rotation direction and routing of the poly V-belt is correct when installed. see scheme 30
Remove M8 x 40 bolt from V-belt tensioning element threaded bore. (Scheme 20) Torque components to proper specifications. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/cooling-fan/#electric-coolant-fans) table.

TORQUE SPECIFICATIONS

Application	Ft. Lbs. (N.m)
Coolant Fan Control Thermo Switch	26 (35)
INCH Lbs. (N.m)
A/C High Pressure Sensor	(1) 44 (5)
Coolant Fan To Radiator Cowl	89 (10)
Condenser To Radiator	89 (10)
Radiator Cowl To Radiator	89 (10)
Radiator To Lock Carrier	133 (15)
(1) A/C refrigerant does not need to be discharged. Use new "O" ring.

(1)	A/C refrigerant does not need to be discharged. Use new "O" ring.

TORQUE SPECIFICATIONS