Rain Sensor: Testing and Inspection

TROUBLESHOOTING

The rain sensor has two levels of fault detection as described below:

1. FAULT A
Fault A is indicated when the sensor has detected that the sensor servo operating point is above the expected limits. This is an indication of damage to the wind screen in the area of the coupler or the sensor has been removed from the coupler.

2. FAULT B
Fault B is indicated when the sensor has detected that it no longer is responding to rain signals.
This is an indication of damage to the wind screen in the area of the coupler or, more likely, that the sensor has detected an electrical failure within the sensor.

3. ATTACHMENT GRADE VALUE
Attachment grade is used to determine when a fault in A is detected. The attachment grade value is set at 140. This allows the product to operate in all conditions other than the most severe damage the wind screen.

4. USE SENSITIVITY ADJUSTMENT TO INDICATE FAULT
A method to indicate detected faults is available to a service garage technician by using the sensitivity input and the wipers as an indicator. The service method is described as follows:
- With ignition "ON", move the sensitivity adjustment to the high sensitivity setting.
- Decrease the sensitivity by one setting.
- If a wipe occurs, then Fault A has been detected and the service technician should assure that the coupler area on the wind screen is not damaged and the sensor is secured to the coupler.
- Decrease the sensitivity one more setting.
- If a wipe occurs, then Fault B has been detected and the sensor should be removed and replaced with a known good sensor.

CAUTION: When the ignition key is "ON" and the multifunction switch is in the auto position the wiper could operate in the following conditions.
- Be careful not to touch the upper sensor front window glass.
- Be careful not to scrub the upper sensor front window glass with a cloth.
- Be careful not to vibrate the front window glass.