Nissan Sentra B18 (2020-2025) Service Manual: System Description

System Description

SYSTEM DIAGRAM

OUTLINE

The front wiper is controlled by each function of the BCM and IPDM E/R.

Control by BCM:

• Combination switch reading function

• Front wiper control function

Control by IPDM E/R:

• Front wiper control function

• Relay control function

INPUT SIGNAL AND OUTPUT SIGNAL

Signal name	Input	Output	Description
Combination switch (wiper and washer switch)	Combination switch (wiper and washer switch)	BCM	Transmits the combination switch (wiper and washer switch) signal for front wiper and washer system operation to the BCM.
Nissan Sentra Vehicle speed signal	ABS actuator and electric unit (control unit)	BCM (CAN)	Transmits the Nissan Sentra vehicle speed signal via CAN communication.
Front wiper request signal	BCM	IPDM E/R (CAN)	Transmits the front wiper request signal via CAN communication.
Front wiper stop position signal	Front wiper motor	IPDM E/R	Inputs the front wiper motor stop position signal to the IPDM E/R.
Front wiper stop position signal	IPDM E/R	BCM (CAN)	Transmits the front wiper motor stop position signal via CAN communication.

FRONT WIPER BASIC OPERATION

• The BCM detects the combination switch (wiper and washer switch) condition by the combination switch reading function.

• The BCM transmits the front wiper request signal to the IPDM E/R via CAN communication depending on each operating condition of the front wiper.

• The IPDM E/R turns ON/OFF the integrated front wiper relay and the front wiper high relay according to the front wiper request signal. The IPDM E/R provides the power supply to operate front wiper HI/LO operation.

FRONT WIPER LO OPERATION

• The BCM transmits the front wiper request signal (LOW) to the IPDM E/R via CAN communication according to the front wiper LO operating condition.

  Front wiper LO operating condition:

  • Ignition switch ON

  • Front wiper switch LO or front wiper switch MIST (while pressing)

• IPDM E/R turns ON the integrated front wiper relay according to the front wiper request signal (LOW).

FRONT WIPER HI OPERATION

• BCM transmits the front wiper request signal (HIGH) to IPDM E/R via CAN communication according to the front wiper HI operating condition.

  Front wiper HI operating condition:

  • Ignition switch ON

  • Front wiper switch HI

• The IPDM E/R turns ON the integrated front wiper relay and the front wiper high relay according to the front wiper request signal (HIGH).

FRONT WIPER INT OPERATION

• The BCM transmits the front wiper request signal (LOW) to the IPDM E/R via CAN communication depending on the front wiper INT operating condition and intermittent operation delay interval according to the wiper volume dial position.

  Front wiper INT operating condition:

  • Ignition switch ON

  • Front wiper switch INT

• The IPDM E/R turns ON the integrated front wiper relay so that the front wiper is operated only once according to the front wiper request signal (LOW) and front wiper request signal (RETURN).

• The BCM detects stop position/except stop position of the front wiper motor according to the front wiper stop position signal received from the IPDM E/R via CAN communication.

• The BCM transmits the front wiper request signal (LOW) again after the intermittent operation delay interval.

Note:

The front wiper INT operation setting of the linked or not linked with Nissan Sentra vehicle speed can be changed by the combination meter setting.

Front wiper intermittent operation with Nissan Sentra vehicle speed

• The BCM calculates the intermittent operation delay interval from the following:

  • Nissan Sentra Vehicle speed signal

  • Wiper volume dial position

Unit: Second

Intermittent operation delay Interval:

Wiper volume dial position	Intermittent operation interval	Nissan Sentra Vehicle speed
		0 – 18.6 MPH (0 – 30 km/h)	15.5 – 37.3 MPH (25 – 60 km/h)	34.2 – 65.2 MPH (55 – 105 km/h)	62.1 MPH (100 km/h) or more
1	Long ↑ ↓ Short	21.0	18.9	15.8	12.6
2		11.2	10.1	8.4	6.7
3		5.6	5.0	4.2	3.4
4		2.8	2.5	2.1	1.7
5		1.4	1.3	1.1	0.8

FRONT WIPER AUTO STOP OPERATION

• The BCM transmits the front wiper request signal (RETURN) to the IPDM E/R via CAN communication when the front wiper switch is turned OFF.

• The IPDM E/R detects the front wiper stop position signal from the front wiper motor to find out the front wiper motor position (stop position/except stop position).

• When the IPDM E/R receives the front wiper request signal (RETURN) from the BCM and the front wiper motor position is not in the stop position, the IPDM E/R turns ON the front wiper relay until the front wiper motor returns to the stop position.

• When the front wiper motor returns to the stop position, the IPDM E/R transmits the front wiper status signal to the BCM via CAN communication.

• When the BCM receives the front wiper status signal from the IPDM E/R, the BCM transmits the front wiper request signal (STOP) to the IPDM E/R via CAN communication.

FRONT WIPER OPERATION LINKED WITH WASHER

• The BCM transmits the front wiper request signal (LOW) to the IPDM E/R via CAN communication according to the washer linked operating condition of the front wiper.

• The BCM transmits the front wiper request signal (LOW) so that the front wiper operates approximately 2 times when the front washer switch OFF is detected.

  Washer linked operating condition of front wiper:

  • Ignition switch ON

  • Front washer switch ON (0.4 second or more)

• The IPDM E/R turns ON the integrated front wiper relay according to the front wiper request signal (LOW).

• The washer pump is grounded through the combination switch with the front washer switch ON.