Wiper and Washer Systems: Description and Operation

FRONT WIPER AND WASHER SYSTEM

System Description
- All front wiper relays (HI LO) are included in IPDM E/R.
- Wiper switch (combination switch) is composed of a combination of 5 output terminals and 5 input terminals. Terminal combination status is read by BCM when switch is turned ON.
- BCM controls front wiper LO HI and INT (intermittent) operation.
- IPDM E/R operates wiper motor according to CAN communication signals from BCM.

Power is supplied at all times
- through 50 A fusible link (letter F located in fusible link box.)
- to BCM (body control module) terminal 7
- through 20 A fuse [No.74 located in IPDM E/R (intelligent power distribution module engine room)]
- to front wiper relay [built in IPDM E/R (intelligent power distribution module engine room)]
- through 15 A fuse [No.73 located in IPDM E/R (intelligent power distribution module engine room)]
- to CPU (central processing unit) in the IPDM E/R (intelligent power distribution module engine room).

When the ignition switch ON or START position power is supplied
- through 10 A fuse [No.1 located in fuse block (J/B)]
- to BCM (body control module) terminal 35 and
- through 10 A fuse [No.80 located in IPDM E/R (intelligent power distribution module engine room)]
- to front wiper relay [built in IPDM E/R (intelligent power distribution module engine room)] and
- to front wiper high relay [built in IPDM E/R (intelligent power distribution module engine room)]
- through 10 A fuse [No.87 located in IPDM E/R (intelligent power distribution module engine room)]
- through IPDM E/R (intelligent power distribution module engine room) terminal 18
- to front washer motor terminal 2.

Ground is supplied
- to BCM (body control module) terminal 8
- through grounds E17 and E43
- to IPDM E/R (intelligent power distribution module engine room) terminals 14 and 45
- through grounds E17 and E43
- to combination switch (wiper switch) terminal 12
- through grounds M30 and M66.

LOW SPEED WIPER OPERATION
When front wiper switch is in LO position BCM detects the LO position of the front wiper switch by BCM wiper switch reading function.

BCM sent front wiper request signal (LO) to IPDM E/R by CAN communication line
- from BCM terminals 70 and 71
- to IPDM E/R terminals 48 and 49.

When IPDM E/R receives front wiper request signal (LO) it turns ON front wiper relay (built in IPDM E/R)

power is supplied
- to front wiper motor terminal 3
- through IPDM E/R terminal 31 and front wiper relay and front wiper high relay.

Ground is supplied
- to front wiper motor terminal 4
- through grounds E17 and E43.

with power and ground is supplied the front wiper motor operates at low speed.

HI SPEED WIPER OPERATION
When front wiper switch is in HI position BCM detects the HI position of the front wiper switch by BCM wiper switch reading function.
BCM sent front wiper request signal (HI) to IPDM E/R by CAN communication line
- from BCM terminals 70 and 71
- to IPDM E/R terminals 48 and 49.

When IPDM E/R receives front wiper request signal (HI) it turns ON front wiper relay (built in IPDM E/R) power is supplied
- to front wiper motor terminal 2
- through IPDM E/R terminal 30 and front wiper relay and front wiper high relay. Ground is supplied
- to front wiper motor terminal 4
- through grounds E17 and E43.

with power and ground is supplied the front wiper motor operates at high speed.

INTERMITTENT OPERATION
The front wiper motor operates the wiper arms one time at low speed at a set interval of wiper volume switch and vehicle speeds this feature is controlled by the BCM and IPDM E/R.

When front wiper switch is in INT position BCM detects INT position of the front wiper switch by BCM wiper switch reading function. BCM performs the following operations
- When BCM detects ON/OFF status of intermittent operation dial positions 1, 2 and 3 it determines wiper dial position status. Refer to "Wiper Dial Position Setting".
- BCM calculates operation interval from wiper dial position and vehicle speed signal received from combination meter with CAN communications.
- BCM sends front wiper request signal (INT) to IPDM E/R at calculated operation interval.
- When IPDM E/R receives front wiper request signal (INT) it turns ON internal front wiper relay. It then sends auto stop signal to BCM and conducts intermittent front wiper motor operation.

With power is and ground supplied circuit routed front wiper operates at intermittent.

AUTO STOP OPERATION
With wiper switch turned OFF wiper motor will continue to operate until wiper arms reach windshield base.

When wiper arms are not located at base of windshield with wiper switch OFF power is provided
- from IPDM E/R terminal 31
- to front wiper motor terminal 3 in order to continue wiper motor operation at low speed.

When wiper arms reach base of windshield front wiper motor terminals 1 and 4 are connected and ground is supplied
- to IPDM E/R terminal 38
- through front wiper motor terminal 1
- through front wiper motor terminal 4
- through ground E17 and E43.

Then the IPDM E/R sends auto stop operation signal to BCM with CAN communication line.

When BCM receives auto stop operation signal BCM sends wiper stop signal to IPDM E/R with CAN communication line.

IPDM E/R stops wiper motor. Wiper motor will then stop wiper arms at the STOP position.

WASHER OPERATION
When wiper switch is in front wiper washer position BCM detects front wiper washer signal by BCM wiper switch reading function (Refer to "BCM Wiper Switch Reading Function") combination switch (wiper switch) ground is supplied
- to front washer motor terminal 1
- through combination switch (wiper switch) terminal 11
- to combination switch (wiper switch) terminal 12
- through grounds M30 and M66

With ground is supplied front washer motor is operated.

When BCM detects that front washer motor has operated for 0.4 seconds or linger BCM operates front wiper motor for low speed.

When BCM detects washer switch is OFF low speed operation cycles approximately 3 times and stops.

MIST OPERATION
When the wiper switch is turned to the mist position wiper low speed operation cycles once and then stops.

For additional information about wiper operation under this condition. Refer to "LOW SPEED WIPER OPERATION".

If the switch is held in the mist position low speed operation continues.

FAIL-SAFE FUNCTION
IPDM E/R includes a fail-safe function to prevent malfunction of electrical components controlled by CAN communications in CAN communications occurs.

When fail-safe status is initiated IPDM E/R remains in steady unit signals are received.

BCM WIPER SWITCH READING FUNCTION
BCM reads combination switch (wiper switch) status and controls front wipers based on the results.

BCM is a combination of 5 output terminals (OUTPUT 1 - 5) and 5 input terminals (INPUT 1 - 5). It reads 20 types of switch data and 5 types of diagnosis data.

OPERATION DESCRIPTION
BCM continuously outputs power voltage from input terminals (INPUT 1 - 5). At this time output terminals (OUTPUT 1 - 5) operate transistors in sequence and carry current. If any switch (or switches) becomes ON at this time the input terminal corresponding to that switch detects current flowing and BCM determines that the switch is ON.

BCM:

TABLE OF BCM - COMBINATION SWITCH OPERATIONS
BCM reads operation status of combination switch using combinations shown in table.

SAMPLE OPERATION: (WIPER SWITCH TURNED TO LO POSITION)
- When wiper switch is turned to LO position front wiper LO contact inside combination switch becomes ON. At this time OUTPUT 3 transistor operates and BCM detects flow of current at INPUT 1.
- When OUTPUT 3 transistor is ON and BCM detects current flowing at INPUT 1 BCM determines that wiper switch is at LO. BCM uses CAN communication and sends front wiper signals to IPDM E/R.
- When OUTPUT 3 transistor operates again and BCM again detects current flowing at INPUT 1 it confirms that front wiper LO operation is continuing.

NOTE: Each OUTPUT terminal transistor operates at 10 ms intervals. Therefore a delay occurs between the switch becoming ON and operation of the electric load. However this delay is so small it is undetectable.

OPERATING MODES
The following operation modes exist for combination switch reading function.

Normal Status
When BCM is not in sleep status OUTPUT terminals (1 - 5) each turn ON-OFF every 10 ms.

Sleep Status
When BCM is in sleep status output from OUTPUT 1 and 2 transistors stops with BCM entering a power-saving mode. OUTPUT (3 - 5) turns ON-OFF every 60 ms and only input from lighting switch system is accepted.

INTERMITTENT OPERATION
Wiper intermittent operation delay interval is determined from a combination of 3 switches (intermittent operation dial position 1 intermittent operation dial position 2 and intermittent operation dial position 3) and vehicle speed signal.

During each intermittent operation delay interval BCM sends front wiper request signal to IPDM E/R.

Wiper Dial Position Setting:

Example: For wiper dial position 1...

Using combination switch reading function BCM detects ON/OFF status of intermittent operation dial positions 1 2 and 3.

When combination switch status is as listed below BCM determines that it is wiper dial position 1.
- Intermittent operation dial position 1: ON (input 3 and output 1 are conducting.)
- Intermittent operation dial position 2: ON (input 5 and output 1 are conducting.)
- Intermittent operation dial position 3: ON (input 4 and output 2 are conducting.)

BCM determines front wiper intermittent operation delay interval from wiper dial position 1 and vehicle speed and sends wiper request signal (INT) to IPDM E/R.

CAN Communication Unit:

TYPE 1:

TYPE 2:

CAN Communication System Description
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle and each control unit shares information and links with other control units during operation (not independent). In CAN communication control units are connected with 2 communication lines (CAN H line CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.