RAM 2500 Van V8-5.2L Prop VIN 2 (2000)
The resistance selected by the stalk switch is used to set the delay time between wipe cycles.
The Intermittent Wipe Delay Time is also adjusted based upon Vehicle Speed. When the Vehicle Speed is < 10 MPH then the driver selected
Delay Time is doubled providing a range from 1 second to 36 seconds. When the vehicle speed is > 10 MPH then the driver selected Delay Time
is not adjusted. An immediate Low Speed mode Wipe cycle will occur and a new Delay Time interval will start if the driver changes the current
selected Delay Time to a shorter interval. The speed signal is provided to the CTM from the PCM over the CCD bus.
Wipe After Wash Operation
Wipe after Wash operation activates the Wiper system when the Wash button is pressed. Wiper after Wash operation is available while the wiper
switch is OFF or in Intermittent mode, and operates the Wipers in a Low Speed continuous cycling mode while the Wash button is held ON. After
the Wash button is released, 2 additional complete cycles are performed at Low Speed. The Wiper system returns to the previous mode of
operation following the completion of the additional Wipe cycles.
Self Calibration
A self calibration feature is used to eliminate performance variations due to tolerances in the resistances of the intermittent wiper switch.
Following a power on reset, a default value is copied to a battery backed RAM memory location. If a valid resistance value greater than the current
battery backed compensation value is measured during intermittent wiper operation, and it is present for 8 consecutive samples, the compensation
value is replaced by the average of the compensation value and the new resistance value. This compensation value is used to calculate the
intermittent wiper delay, using the following formula:
Delay in seconds = 0.5 + 17.5* (resistance value/compensation value)
Three EEPROM locations have been provided to allow for optional calibration of the intermittent wipers. One location specifies a constant which
will override the battery backed compensation value. The other locations specify constants which will override the default Offset and slope used in
converting resistance to time delay.
Failed Wiper Park Switch
A failed Wiper Park Switch is determined by the CTM "C1" PIN #11 input remaining high for eight seconds when the wiper system is in
intermittent mode. Once detected, a code flag will be set in the EEPROM fault record byte.
Once the Failed Wiper Park Switch fault is set, the intermittent wiper function will not operate until a low is seen on the CTM "C1" PIN #11 input
with the ignition ON. The code flag may only be cleared manually using a DRB.
