Disconnect the vacuum hose 26 from the vacuum manifold.
Connect the vacuum pump and create a vacuum.
Turn the ignition key to the START position.
ATTENTION! Coolant temperature must be below 40°C.
If the vacuum remains at the same level, then see step A). If not - item B).
A) Switch off the ignition.
Disconnect the 8-pin connector on the control box.
Measure the voltage between Blue/Red (+) and Cherny (-) contacts on the main wiring harness.
Turn the ignition key to the START position.
If battery voltage is present, the solenoid valve should be replaced.
If there is no voltage, then measure the voltage between Blue/Red (+) contact and ground with the ignition key in the START position.
If there is battery voltage, then an open in the Black conductor between the control box and point G7 should be corrected.
If there is no voltage, then you should check for an open Blue / Red wire between the control box and terminal 27 of the control unit. If the wire is normal, then you should refer to the diagnostics section of the inputs of the control modules.
B) Start the engine and let it warm up to operating temperature until the cooling fan turns on.
Create a vacuum.
If the solenoid valve is holding a vacuum, then the vacuum line should be checked for proper connection, cracks, a plug, or a disconnected hose.
If the valve does not hold vacuum, then disconnect the 8-pin connector on the control box.
Next, measure the voltage between Blue/Red (+) and Cherny (-) contacts in the main wiring harness.
If voltage is present, refer to the control module input diagnostics section.
If there is no voltage, then the solenoid valve should be replaced.