Rear Window Wiper/Washer System (E39 Wagon And E53)
The system is included in the scope of ZKE however is not controlled directly by the GM. The control electronics are integrated into the rear wiper motor assembly. The control electronics contains two hall sensors, one for monitoring park position and other for the end stop, or to signal reverse direction of the wiper motor. The control electronics are connected to the vehicle electrical system via a single seven pin connector.
The rear wiper system is operator controlled through the wiper stalk switch providing the following functions:
- Intermittent rear window wiping
- Programmed rear window wiping interval
- Operation of the rear window washer
Pressing the wiper stalk forward to the first detent activates the rear wiper in the intermittent mode.
The timed interval is approximately 7-12 seconds. The full sweep and park positions are recognized by the two hall sensors on the motor gear assembly. If the wiper is switched OFF, the wiper blade will return to the park position.
The programmed wiper interval procedure is as follows:
- Briefly switch the rear wiper ON/OFF
- Wait the desired interval time
- Switch the rear wiper ON again
- The OFF time will be the programmed interval - up to approximately. 30 seconds
Rear window washing is activated by pressing the wiper stalk switch to the full forward position. The washer pump operates followed by two full wiping cycles. The wipers will then switch to the intermittent wiping mode. Additionally, the system automatically controls the following safety and convenience features:
- Wiper interrupt with the rear glass opened
- Wiping interrupt with a blocked wiper arm
- Continuous wiping when the vehicle is shifted into reverse
When the transmission is shifted into reverse, the wiper will switch to continuous operation until the vehicle is shifted out of reverse. This signal (high) is provided by the LCM III when it activates the back up lights.