Wiper and Washer Systems: Description and Operation
System Description
- All front wiper relays (HI LO) are included in IPDM E/R (intelligent power distribution module engine room).
- 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 (body control module) controls front wiper LO HI and INT (intermittent) operation.
- IPDM E/R (intelligent power distribution module engine room) operates wiper motor according to CAN communication signals from BCM (body control module).
Power is supplied at all times
- through 50 A fusible link (letter F located in fusible link box.)
- to BCM (body control module) terminal 55
- through 10 A fuse [No.18 located in fuse block (JIB)]
- to BCM (body control module) terminal 42
- through 20 A fuse [No.73 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.78 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)
- through 10 A fuse [No.71 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 iqnition switch ON or START position power is supplied
- through 10 A fuse [No.1 located in fuse block (JIB)]
- to BCM (body control module) terminal 38
- through ignition relay [built 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.84 located in IPDM E/R (intelligent power distribution module engine room)] and
- through IPDM E/R (intelligent power distribution module engine room) terminal 44
- to front washer motor terminal 2.
Ground is supplied
- to BCM (body control module) terminal 52
- through grounds M30 and M66
- to IPDM E/R (intelligent power distribution module engine room) terminals 38 and 60
- through grounds El7and E43
- to combination switch (wiper switch) terminal 12
- through grounds M30 and M66.
LOW SPEED WIPER OPERATION
When wiper switch is in LO position BCM detects low speed wiper ON signal by BCM wiper switch reading function.
BCM sends front wiper request signal (LO) with CAN communication line
- from BCM terminals 39 and 40
- 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 21 and front wiper relay and front wiper HI relay.
Ground is supplied
- to front wiper motor terminal 4
- through grounds E17 and E43.
With power and ground supplied the front wiper motor operates at low speed.
HI SPEED WIPER OPERATION
When wiper switch is in HI position BCM detects high speed wiper ON signal by BCM wiper switch reading function.
BCM sends front wiper request signal (HI) with CAN communication line
- from BCM terminals 39 and 40
- 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 31 and front wiper relay and front wiper HI relay.
Ground is supplied
- to front wiper motor terminal 4
- through grounds E17 and E43.
With power and ground supplied the front wiper motor operates at high speed.
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 (Combination switch output 3 and input 1 are performing.)
- Intermittent operation dial position 2: ON (Combination switch output 5 and input 1 are performing.)
- Intermittent operation dial position 3: ON (Combination switch output 4 and output 2 are performing.) 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.
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 ground is provided
- from terminal 21 of the IPDM E/R
- 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 terminal 32 of IPDM E/R
- through front wiper motor terminals 1 and 4
- through grounds 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 with ignition switch ON BCM detects front wiper switch is ON the washer position by BCM wiper switch reading function. (Refer to COMBINATION SWITCH.
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 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.
COMBINATION SWITCH READING FUNCTION
Description
- BCM reads combination switch (wiper) status and controls related systems such as head lamps and wip- ers according to the results.
- BCM reads information of a maximum of 20 switches by combining five output terminals (OUTPUT 1-5) and five input terminals (INPUT 1-5).
Operation description
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.
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.
Information Bus