Disconnect the #31 solenoid valve vacuum hose from the vacuum manifold.
Disconnect the #30 solenoid valve vacuum hose from the vacuum manifold and connect the vacuum pump.
Start the engine and create a vacuum.
ATTENTION! Coolant temperature must be below 70°C.
If the solenoid valve holds a vacuum, then see item A), if not - item B).
A) Stop the engine.
Disconnect the 4-pin connector near the solenoid valve.
Start the engine.
Measure the voltage between White/Blue (+) and Cherny (-) contacts on the main wiring harness.
If battery voltage is present, the solenoid valve should be replaced.
If there is no voltage, then measure the voltage between White/Blue (+) contact and weight.
If there is battery voltage, then you should repair the open in the Black conductor between the solenoid valve and point G5.
If there is no voltage, then check for an open Blue / Yellow wire between the solenoid valve and terminal 26 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) Stop the engine.
Block the rear wheels and apply the parking brake. Jack up the front of the vehicle and support it securely with jack stands.
Start the engine.
Shift the transmission into second gear and accelerate the engine to speeds above 25 km/h.
Create a vacuum.
If the solenoid valve holds a vacuum, then see item B1), if not - item B2).
B1) Warm up the engine to operating temperature until the cooling fan turns on.
Create a vacuum.
If the solenoid valve is holding a vacuum, then check the vacuum line for proper connection, cracks, blockage, or hose disconnection.
If the solenoid valve does not hold vacuum, then refer to the control module input diagnostics section.
B2) Stop the engine.
Disconnect the 4-pin connector near the solenoid valve.
Start the engine and accelerate it to over 25 km/h.
Measure the voltage between White/Blue (+) and Cherny (-) contacts on the main wiring harness.
If battery voltage is present, refer to the Control Module Input Diagnostics section. If there is no voltage, then the solenoid valve should be replaced.