Volledigheidshalve nog wat info : een technische nota die duidelijke uitleg geeft over de werking van de enerzijds de condensor-ventilator en anderzijds de motorkoeling-ventilator en de mogelijke fouten/problemen :
A cooling module located under the Passenger side guard is used to control the radiator fan, condenser fan and the
compressor clutch activation. This cooling module receives information from various areas such as the ignition switch, A/C
request signal, high side A/C system pressure, coolant temperature and engine RPM. From the information received the
module will operate the engine and condenser fans in four different mode types.
The cooling module has a internal diagnostic system that will turn on the instrument panel A/C / radiator warning lamp if a
problem is detected. An “emergency fan activation mode” is also used in the case of an issue with the module or sensors. An
appropriate scan tool can be used to read and clear any DTC’s relating to this module.
The major issue with the cooling module is moisture entry owing to the location under the guard. The moisture will cause
internal damage to the module and the fans will operate in “emergency fan activation” mode.
A cooling module located under the Passenger side guard is used to control the radiator fan, condenser fan and the
compressor clutch activation. This cooling module receives information from various areas such as the ignition switch, A/C
request signal, high side A/C system pressure, coolant temperature and engine RPM. From the information received the
module will operate the engine and condenser fans in four different mode types.
The cooling module has a internal diagnostic system that will turn on the instrument panel A/C / radiator warning lamp if a
problem is detected. An “emergency fan activation mode” is also used in the case of an issue with the module or sensors. An
appropriate scan tool can be used to read and clear any DTC’s relating to this module.
The major issue with the cooling module is moisture entry owing to the location under the guard. The moisture will cause
internal damage to the module and the fans will operate in “emergency fan activation” mode.
ASTRA / ZAFIRA COOLING FAN ISSUES
Cooling Fans Stay On—Both or one fan stay on after ignition is turned off. Water in cooling module. Fans
come on even when engine is cold, faulty A/C pressure transducer.
Missing Cooling Fan Speeds—Check resistor pack on the radiator fan. Possible broken resistance wire.
Fans Not Operating—Relay fault, highest fan speed Black relay (DTC P1481) in engine bay and low and
medium speeds White relays (P1482 / P1483). 40 amp fuse in engine bay. Fuse 11 in fuse box. Faulty ECU,
no earth circuit for relay. Faulty ignition switch or A/C switch.
Dash warning lamp to indicate cooling fan fault.
FAN ACTIVATION AND CUT OFF VIA TEMPERATURE AND A/C PRESSURE
FAN SPEED ACTIVATION VIA COOLANT TEMPERATURE
FAN ON OFF
NO FAN OPERATION LESS THAN 100°C
SPEED 1-BOTH FANS IN SERIES 100°C LESS THAN 95°C
SPEED 2-BOTH FANS IN PARALLEL VIA RESISTORS GREATER THAN 105°C LESS THAN 105°C
SPEED 3-CONDENSER FAN HAS BATTERY VOLTAGE.
RADIATOR FAN VIA RESISTOR
N/A N/A
SPEED 4-BOTH FANS IN PARALLEL HAVE BATTERY VOLTAGE
GREATER THAN 110°C LESS THAN 105°C
FAN SPEED ACTIVATION VIA A/C PRESSURE (IN kPa)
FAN ON OFF
SPEED-1 BOTH FANS IN SERIES GREATER THAN 1200 LESS THAN 900
SPEED-2 BOTH FANS IN PARALLEL VIA RESISTORS GREATER THAN 1700 LESS THAN 1400
SPEED 3-CONDENSER FAN HAS BATTERY VOLTAGE.
RADIATOR FAN VIA RESISTOR
GREATER THAN 2100 LESS THAN 1800
SPEED-4 BOTH FANS IN PARALLEL HAVE BATTERY GREATER THAN 3000 LESS THAN 2300
A/C COMPRESSOR ACTIVATION DESCRIPTION
When the A/C Switch is activated battery voltage is sent to the SIMTEC module (engine ECU) terminal A11. The
A/C compressor is commanded ON, the engine idle speed is then increased to compensate for the extra load of
the compressor activation. The SIMTEC module switches, terminal A51 to zero volts, this signal is then applied
to the cooling module which inturn activates the compressor clutch. The cooling fan is also activated on low
speed until a temperature or pressure increase occurs.
A/C COMPRESSOR ACTIVATION ISSUES
Faulty pressure transducer.
Compressor magnetic coil open circuit.
Faulty compressor clutch relay.
Cooling module faulty.
Refrigerant quantity not to specification.
Engine idle too low, below 600 rpm.
Faulty coolant temperature switch.
Condenser fan not operating.
Restriction or blockage in A/C system circuit.
Engine overheating through faulty thermostat, radiator or coolant leak.