System Description
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 (body control module) 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.
OUT LINE
Power is supplied at all times
- through 40 A fusible link (letter F, located in fuse, fusible link and relay box)
- to BCM terminal 55,
- through 10 A fuse [No.18 located in fuse block (J/B)]
- to BCM terminal 42,
- through 20 A fuse (No.73 located in IPDM E/R)
- to front wiper relay, located in IPDM E/R,
- through 15 A fuse (No.78 located in IPDM E/R)
- to CPU located in IPDM E/R,
- through 10 A fuse (No.71 located in IPDM E/R)
- to CPU located in IPDM E/R.
When ignition switch is in ON or START position, power is supplied
- to ignition relay, located in IPDM E/R, from battery direct
- through 10 A fuse [No.1 located in fuse block (J/B)]
- to BCM terminal 38,
- through ignition relay, located in IPDM E/R
- to front wiper relay, located in IPDM E/R
- to front wiper high relay, located in IPDM E/R
- to CPU located in IPDM E/R,
- through 10 A fuse (No.84 located in IPDM E/R)
- through IPDM E/R terminal 44
- to front washer motor terminal 2.
Ground is supplied
- to BCM terminal 52
- through grounds M30 and M66,
- to IPDM E/R terminals 38 and 60
- through grounds E17, E43 and F152,
- to combination switch terminal 12
- through grounds M30 and M66.
LOW SPEED WIPER OPERATION
When the front wiper switch is in low position, BCM detect low speed wiper ON signal by BCM wiper switch reading function.
BCM sent front wiper request signal (LOW) with CAN communication line
- from BCM terminals 39 and 40
- to IPDM E/R terminals 48 and 49.
When the IPDM E/R receives front wiper request signal (LOW), it turns ON front wiper relay, located in the IPDM E/R, power is supplied
- to front wiper motor terminal 3
- through IPDM E/R terminal 21 and front wiper high relay and front wiper relay.
Ground is supplied
- to front wiper motor terminal 4
- through grounds E17, E43 and F152.
With power and ground is supplied, front wiper motor operates at low speed.
HIGH SPEED WIPER OPERATION
When the front wiper switch is in HI position, BCM detect high speed wiper ON signal by BCM wiper switch reading function.
BCM sent front wiper request signal (HI) with CAN communication line
- from BCM terminals 39 and 40
- to IPDM E/R terminals 48 and 49.
When the IPDM E/R receives front wiper request signal (HI), it turns ON front wiper relay, located in IPDM E/R, power is supplied
- to front wiper motor terminal 2
- through IPDM E/R terminal 31 and front wiper high relay and front wiper relay.
Ground is supplied
- to front wiper motor terminal 4
- through grounds E17, E43 and F152.
With power and ground is supplied, front wiper motor operates at high speed.
INTERMITTENT OPERATION
Front wiper intermittent operation delay interval is determined from a combination of 3 switches (intermittent operation dial position 1, 2, and 3) and vehicle speed signal.
After each intermittent operation delay interval, BCM sends front wiper request signal to IPDM E/R.
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, BCM determines that it is wiper dial position 1.
- Intermittent operation dial position 1: ON (Continuity exists between combination switch output 3 and input 1.)
- Intermittent operation dial position 2: ON (Continuity exists between combination switch output 5 and input 1.)
- Intermittent operation dial position 3: ON (Continuity exists between combination switch output 4 and input 2.)
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 the wiper arms are not located at base of windshield with wiper switch OFF, ground is provided
- from IPDM E/R terminal 21
- to front wiper motor terminal 3, in order to continue wiper motor operation at low speed
- to IPDM E/R terminal 32
- through front wiper motor terminals 1 and 4
- through grounds E17, E43 and F152.
When the wiper arms reach base of windshield, front wiper motor terminals 1 and 4 are connected, and ground is supplied
Then the IPDM E/R sends auto stop operation signal to BCM with CAN communication line.
When the 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 the wiper switch is in front wiper washer position, BCM detect front wiper washer signal by BCM wiper switch reading function. (Refer to "COMBINATION SWITCH READING FUNCTION" )
Combination switch ground is supplied
- to front washer motor terminal 1
- through combination switch terminal 11
- to combination switch terminal 12
- through grounds M30 and M66.
With ground is supplied, front washer motor is operated.
When the BCM detects that front washer motor has operated for 0.4 seconds or longer, BCM operates front wiper motor for low speed.
When the BCM detects washer switch is OFF, low speed operation cycles approximately 2 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 switch is held in mist position, low speed operation continues.
FAIL-SAFE FUNCTION
If an abnormality occurs in CAN communications, IPDM E/R holds the condition just before fail-safe status is initiated until ignition switch is turned off. (If wipers were operating in LO just before the initiation of fail-safe status, they continue to operate in LO until ignition switch is turned OFF)
COMBINATION SWITCH READING FUNCTION
Description
- BCM reads combination switch (wiper) status, and controls related systems such as headlamps and wipers, 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 activates transistors of output terminals (OUTPUT 1-5) periodically, and allows current to flow in turn.
- If any (1 or more) switches are turned ON, circuit of output terminals (OUTPUT 1-5) and input terminals (INPUT 1-5) becomes active.
- At this time, transistors of output terminals (OUTPUT 1-5) are activated to allow current to flow. When voltage of input terminals (INPUT 1-5) corresponding to that switch changes, interface in BCM detects voltage change, and BCM determines that switch is ON.
Sample Operation: (When Wiper Switch Turned to LOW Position)
- When wiper switch is turned to LOW position, front wiper LOW contact in combination switch turns ON. At this time if OUTPUT 1 transistor is activated, BCM detects that voltage changes in INPUT 3.
- When BCM detects that voltage changes in INPUT 3 while OUTPUT 1 transistor is ON, it judges that front wiper switch is in LOW position. Then BCM sends front wiper request signal (LO) to IPDM E/R using CAN communication.
- If BCM detects that voltage changes in INPUT 3 when OUTPUT 1 transistor is activated again, it recognizes that wiper switch is still in LOW position.
NOTE: Each OUTPUT terminal transistor is activated at 10 ms intervals. Therefore after switch is turned ON, electrical loads are activated with time delay. But this time delay is so short that it cannot be detected by human senses.
Operation Mode
Combination switch reading function has operation modes shown.
1. Normal status
- When BCM is not in sleep status, OUTPUT terminals (1-5) each turn ON-OFF every 10 ms.
2. Sleep status
- When BCM is in sleep status, transistors of OUTPUT (1 and 5) stop the output, and BCM enters low current consumption mode. OUTPUT (2, 3, and 4) turn ON-OFF every 60 ms, and only input from light switch system is accepted.