85A-8V1 MR-376-X76-85A000$040.mif
85A
UCH
Vdiag No.: 0F
Windscreen washing/wiping
The UCH receives the wiper speed, windscreen wiper park position and windscreen washer signals.
This ensures the following functions:
– intermittent wiper speed,
– extended wiper time after washing,
– return to park position.
In the park position, the switch is closed to earth, and the UCH receives logical signal 0.
This function is only active if + after ignition feed is present.
When the + after ignition feed is switched on, if the windscreen wiper park position is not detected, the wiper motor
relay is held.
Operation is interrupted in the following cases:
– wiper request stopped or no request,
–+ after ignition feed switched off,
– UCH reads park position information.
Detection of the park position should be made during transition and not level, that is, if the wiper stalk is moved from
the intermittent position to the park position while the wiper blade is in the park position and the wiper motor is
running, it will not be stopped until the next reading of the park position. This condition is necessary in order to obtain
an exact park position.
Intermittent
The intermittent wiper speed function is only active if the + after ignition is present and if the switch is in the
intermittent position.
The time delay between two wipes is 5 seconds, and this cannot be modified by the diagnostic tool.
When the windscreen intermittent speed function is activated, the windscreen intermitted speed relay is held by the
UCH until the park position is detected. When the intermittent speed time delay has elapsed, the relay is held again
and the cycle begins again.
Extended wiper time after washing
The UCH does not manage the windscreen washer pump command, it only deals with the windscreen washer
command input to provide screen wiping and the extended wiper time after washing.
This function is only active if + after ignition feed is present.
After the washer pump is activated, the first wiping is performed after a time delay of 750 ms.
When the washing control is pressed briefly, the windscreen wiper performs 1 wiping cycle.
When the washing control is pressed for longer, the UCH activates the windscreen wiper throughout the washing
phase. At the end of the washing phase, the UCH counts the park position status changes in order to stop the
extended wiping phase.
WIPERS - WASHERS
Fault finding – Function
85A-9V1 MR-376-X76-85A000$040.mif
WIPERS - WASHERS
Fault finding – Function85A
UCH
Vdiag No.: 0F
Rear screen washing/wiping
The UCH controls a diode relay which is external to the UCH, by transmitting a + 12 V signal.
The drop in the voltage between the UCH supply voltage and this output should not exceed 2 V.
The UCH receives the intermittent wiper speed, rear wiper park and rear screen washer signals.
This ensures the following functions:
– intermittent wiper speed,
– extended wiper time after washing,
– return to park position.
In the park position, the switch is closed to earth, and the UCH receives logical signal 0.
This function is only active if + after ignition feed is present.
When the + after ignition feed is switched on, if the rear wiper park position is not detected, the wiper motor relay is
held.
Operation is interrupted in the following cases:
– wiper request stopped or no request,
–+ after ignition feed switched off,
– UCH reads park position information.
Detection of the park position should be made during transition and not level, that is, if the wiper stalk is moved from
the intermittent position to the park position while the wiper blade is in the park position and the wiper motor is
running, it will not be stopped until the next reading of the park position. This condition is necessary in order to obtain
an exact park position.
Intermittent
The intermittent wiper speed function is only active if the + after ignition is present and if the switch is in the
intermittent position.
The time delay between two wipes is 5 seconds, and this cannot be modified by the diagnostic tool.
When the rear intermittent speed function is activated, the rear intermittent speed relay is held by the UCH until the
park position is detected. When the intermittent speed time delay has elapsed, the relay is held again and the cycle
begins again.
Extended wiper time after washing
The UCH does not manage the rear washer pump command.
It only deals with the rear screen washer command input to provide wiping and extended wiping after washing.
This function is only active if + after ignition feed is present.
After the washer pump is activated, the first wiping is performed after a time delay of 750 ms.
