Open the control box, disconnect the lower vacuum hose of the solenoid valve from the quadruple branch pipe and connect the vacuum pump.
Disconnect the solenoid valve vacuum hose #21 from the manifold and connect a pressure gauge.
Start the engine.
Caution: The coolant temperature must be below 70°C.
Create a vacuum.
If the pressure gauge shows a vacuum, then A), otherwise B).
A) Warm up the engine to normal operating temperature (the fan should turn on).
Create a vacuum in neutral or PARK position.
If the solenoid valve holds a vacuum, then A1), otherwise B1).
A1) Shift to D3 or D4 and apply vacuum.
If the gauge does not show vacuum, refer to the control module input diagnostics section, otherwise check the vacuum lines for damage, disconnections or blockages.
B1) Disconnect the 8-pin connector from the control box. Measure the voltage between the yellow/white (+) and black (-) terminals of the main harness. If there is voltage, refer to the control module input diagnostics section, otherwise replace the solenoid valve.
B) Disconnect the 8-pin connector from the control box. Measure the voltage between the yellow/white (+) and black (-) terminals of the main harness. If there is voltage, replace the valve, otherwise measure the voltage between the yellow/white (+) terminal and ground. If there is voltage, repair the break in the black wire between the control box and point G7, if not, check for a break in the yellow/white wire between the control box and terminal 19 of the control unit. If the wire is OK, refer to the diagnostics section.
(The original is located on the website: www.hondabook.ru)