DESCRIPTION & OPERATION
The electric cooling fan is controlled by the ECM. (Scheme 1) The ECM uses a remote power output final stage mounted on the fan housing. The power output stage receives power from a 50-amp fuse located in glove box above the fuse bracket. The electric fan is controlled by a pulse width modulated signal from the ECM. The fan is activated based on the ECM calculation (sensing ratio) of
- Coolant outlet temperature.
- Calculated (by ECM) catalyst temperature.
- Vehicle speed.
- Battery voltage.
- Air conditioning pressure (calculated by IHKA and sent via the K-Bus to the ECM). NOTE: If ECM indicates a fault, check fan for freedom of movement.
After the initial test has been performed, the fan is brought up to the specified operating speed. At 10 percent (sensing ratio) the fan runs at 1/3 speed. At a sensing ratio of 90-95 percent, the fan is running at maximum speed. Below 10 percent or above 95 percent, the fan is stationary. The sensing ratio is suppressed by a hysteresis function, preventing speed fluctuation. When A/C is switched on, the electric fan is not immediately activated. After the engine is switched off, the fan may continue to operate at varying speeds (based on ECM calculated catalyst temperature). This will cool the radiator down from a heat surge (up to 10 minutes).
Scheme 1
SYSTEM TESTS
Note. Testing information is not available from manufacturer.
Note. Numbers in text refer to numbers in figures.
Removal & Installation
- Remove front bumper. See «FRONT BUMPER (UP TO 10/03)»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-bumper-up-to-1003) or «FRONT BUMPER (FROM 10/03)»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-bumper-from-1003). Remove front bumper crossmember. See «FRONT BUMPER CROSSMEMBER»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-bumper-crossmember). On 4.4L and 4.6L, lever out expansion rivets. (Scheme 2) Remove screws. Press locking lugs (1) around circumference and remove intake hood. Intake pipe is secured in intake hood by 2 locking lugs (1). Locking lugs are located under intake hood. (Scheme 3) On 3.0L, lever out expansion rivets and remove intake hood. (Scheme 4)
- On all models, disconnect electrical connectors by radiator (2). (Scheme 5) Remove cable tie (1). Remove left and right bolts (2). (Scheme 6) Lever out expansion rivets (1). Remove panels (2) and (3). Remove cooling fan completely with cowl toward bottom. (Scheme 7) Open locks. Remove protective grill (1). (Scheme 8) Remove screws (1). Remove fan impeller (2) from cowl (3). (Scheme 9)
- To install, reverse removal procedure. Attach cowl of auxiliary fan to left and right holders (1). (Scheme 10)
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
FRONT BUMPER (UP TO 10/03)
Note. Numbers in text refer to numbers in figures.
- On vehicles with headlight cleaning system, detach cable tie (1) from hose (2). Unlock hose (3) and detach and seal pump outlet (4). After detaching hose (3), seal pump outlet (4) with rubber plug. (Scheme 11) On all vehicles, remove left and right screws (1) on sides of wheel arch finishers (2). (Scheme 12) Lever out and remove left and right finishers (1, 2). On vehicles with park distance control, disconnect electrical connector on ultrasonic sensor (3) and remove finishers (2). (Scheme 13)
- On all vehicles, raise hood. Remove left and right bumper trim bolts. (Scheme 14) Remove bolts (1). On vehicles with park distance control and/or front fog lights, if necessary, pull bumper trim (2) forward a little and disconnect electrical connections on ultrasonic sensors (3) and fog lights (4). On all vehicles, pull off bumper (2) and set down on a clean surface. (Scheme 15)
- To install, reverse removal procedure. Replace faulty retainers as necessary. (Scheme 16)
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
FRONT BUMPER (FROM 10/03)
Note. Numbers in text refer to numbers in figures.
- Lever out catches (1) on trim (2) with Special Tool (00 9 317). Lever out trim (3) and remove. (Scheme 17) Remove screws (1) on left/right and lift out wheel arch. (Scheme 18) Raise hood. Remove left and right bolts (1). (Scheme 19) Remove screws (1) on bumper trim (2). (Scheme 20)
- Pull bumper trim (1) in direction of travel shown in illustration to unlock catches on holder, then pull off outward from holder. (Scheme 21) On versions without headlight cleaning system, pull bumper trim (1) forward a little. If necessary, disconnect connections on ultrasonic sensors and/or front fog lights (if equipped). Remove bumper trim (1) toward front. (Scheme 21) On version with headlight cleaning system, if necessary, pull bumper trim (3) forward a little. Unlock hose (1) and detach and seal pump outlet (2). Remove bumper trim (1) toward front. (Scheme 22)
- To install, reverse removal procedure. Ensure tabs (1) on bumper trim (2) are not damaged. (Scheme 23) If necessary, replace faulty retainers (1) in carrier (2). (Scheme 24)
Scheme 17
Scheme 18
Scheme 19
Scheme 20
Scheme 21
Scheme 22
Scheme 23
Scheme 24
FRONT BUMPER CROSSMEMBER
Note. Numbers in text refer to numbers in figures.
Note. The following operation is described for left side of vehicle. Proceed in the same way for the right side.
- Remove under body protection. See «UNDER BODY PROTECTION»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__under-body-protection).
- Lever lower trim (3) out of guide (1). Unlock catches (2) and remove trim (3) in direction of arrow shown in illustration. (Scheme 25) Release cable ties (1). Disconnect electrical connectors for horns (2). (Scheme 26) Remove expander rivet (1) from fan impeller (2). (Scheme 27)
- For vertical adjustment, mark position of crossmember (3). (Scheme 28) Remove screws (1). Remove nuts (2) and remove crossmember (3) toward front. (Scheme 28) Remove nut (3) and remove horns (2).
- On vehicles manufactured before 10/03, grind off weld spots (4). Remove holder (5) and protect metal from rusting. (Scheme 29)
- To install, reverse removal procedure. If necessary, replace faulty metal nuts (1). Ensure stud bolts (2) on crossmember (3) are not damaged. (Scheme 30)
Scheme 25
Scheme 26
Scheme 27
Scheme 28
Scheme 29
Scheme 30
FRONT UNDER BODY PROTECTION
Note. Numbers in text refer to numbers in figures.
Remove screws (2, 3). Pull under body protection assembly forward (1) under bumper trim and wheel arch trims (4) on left and right sides. To install, reverse removal procedure. Ensure wheel arch trims (4) are correctly seated. Center under body protection (1) and tighten screws (2, 3). (Scheme 31)
Scheme 31
UNDER BODY PROTECTION
Note. Following procedure is described for left side. Proceed the same way for right side of vehicle.
Note. Numbers in text refer to numbers in figures.
- Remove front bumper. See «FRONT BUMPER (UP TO 10/03)»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-bumper-up-to-1003) or «FRONT BUMPER (FROM 10/03)»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-bumper-from-1003). Remove front underbody protection. See «FRONT UNDER BODY PROTECTION»(/bmw/x5/e53-1999-2003/remont/cooling-fan/#electric-engine-cooling-fans__front-under-body-protection).
- On vehicles manufactured up to 10/03, lever out catches (1) and detach brake air duct (2). (Scheme 32)
- On vehicles manufactured after 10/03, remove expansion rivet (1). Lever out catches (2) and detach brake air duct (3). (Scheme 33) On left side, lever temperature sensor (1) out of fixture (2). Pull temperature sensor (1) with cable grommet (3) out of brake air duct (5). (Scheme 34)
- On all vehicles, remove nuts (1) and remove under body protection (2) in direction of arrow. (Scheme 35)
- To install, reverse removal procedure. Ensure nuts (1) on under body protection are not damaged. (Scheme 36) Ensure fixtures (1, 4) on brake air duct (2, 5) are not damaged. (Scheme 37) Ensure catches (1) on brake air duct (2) are not damaged. (Scheme 38)
