Checking the kickdown solenoid valve:

• Turn on ignition
• Press accelerator pedal to full throttle pressure point; no clicking noise should be heard
• Press accelerator pedal past the full throttle point (kickdown); now the "click" from solenoid valve activation must be heard.
• A second "click" must be heard when releasing the pedal only slightly.

Checking the kickdown speed relay:

The kickdown speed relay on the central electrics board has the task of interrupting the flow of electric power to the solenoid when the pedal is in kick-down position and an engine speed of 5900 rpm +/- 60 rpm has been reached. This interruption causes the transmission to up-shift into the next higher gear.

Checking:

Accelerate the car with full throttle (no kickdown).

The up-shift, e.g. 2 -> , must occur at approx. 5500 to 5700 rpm.

Accelerate the car  with the accelerator pedal in kickdown.

The 2->3 up-shift must occur at 5900 rpm now.

(*note: the speed relay in cars of Japan and USA interrupts power at 5800 rpm +/- 60 rpm)