D2 - Check Mode Select Input Signal
^ Disconnect connector from wiper control module.
^ Measure resistance between circuits 993 (BR/W) and 589 (O).
^ Is resistance between 10.5k ohms and 12.0k ohms?
YES -- Go to D4. D4 - Check Interval Select Input Signal
NO -- Go to D3. D3 - Check Mode Select Signal at Wiper Switch