The signal generated by the speed pulse generator consists of 4 pulses corresponding to each turn of the speedometer cable.
Block the rear wheels and apply the parking brake. Jack up the front of the vehicle and support it with jack stands.
Start the engine and turn on the cruise control.
If the cruise control is not working properly, then check the cruise control speed pulse generator.
If the cruise control is working properly, turn the ignition key to the "ON".
Next, slowly rotating the left front wheel, measure the voltage between 5 (yellow (+)) and 32 (black (-)) contacts.
If the voltage pulsates from 0 to 5 V, then the speed pulse generator is normal.
Otherwise, turn off the ignition.
Next, disconnect the connectors from the control unit.
Turn on the ignition.
While slowly rotating the left front wheel, check the electrical connection between 23 (Black/Yellow (+)) and 32 (black (-)) contacts.
If the electrical connection alternately appears and disappears, then the control unit must be replaced and the procedure repeated.
Otherwise, an open or short circuit in the Yellow wire between the combination meter and terminal 7 of the control unit should be repaired.