GI-32
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
Revision: 2007 April2007 M35/M45
VOLTAGE CHECK METHOD
To help in understanding the diagnosis of open circuits please refer to the previous schematic.
In any powered circuit, an open can be found by methodically checking the system for the presence of voltage.
This is done by switching the DMM to the voltage function.
Connect one probe of the DMM to a known good ground.
Begin probing at one end of the circuit and work your way to the other end.
With SW1 open, probe at SW1 to check for voltage.
voltage; open is further down the circuit than SW1.
no voltage; open is between fuse block and SW1 (point A).
Close SW1 and probe at relay.
voltage; open is further down the circuit than the relay.
no voltage; open is between SW1 and relay (point B).
Close the relay and probe at the solenoid.
voltage; open is further down the circuit than the solenoid.
no voltage; open is between relay and solenoid (point C).
Any powered circuit can be diagnosed using the approach in the previous example.
Testing for “Shorts” in the Circuit
To simplify the discussion of shorts in the system, please refer to the following schematic.
RESISTANCE CHECK METHOD
Disconnect the battery negative cable and remove the blown fuse.
Disconnect all loads (SW1 open, relay disconnected and solenoid disconnected) powered through the
fuse.
Connect one probe of the DMM to the load side of the fuse terminal. Connect the other probe to a known
good ground.
With SW1 open, check for continuity.
continuity; short is between fuse terminal and SW1 (point A).
no continuity; short is further down the circuit than SW1.
Close SW1 and disconnect the relay. Put probes at the load side of fuse terminal and a known good
ground. Then, check for continuity.
continuity; short is between SW1 and the relay (point B).
no continuity; short is further down the circuit than the relay.
Close SW1 and jump the relay contacts with jumper wire. Put probes at the load side of fuse terminal and
a known good ground. Then, check for continuity.
continuity; short is between relay and solenoid (point C).
no continuity; check solenoid, retrace steps.
VOLTAGE CHECK METHOD
Remove the blown fuse and disconnect all loads (i.e. SW1 open, relay disconnected and solenoid discon-
nected) powered through the fuse.
Turn the ignition key to the ON or START position. Verify battery voltage at the battery + side of the fuse
terminal (one lead on the battery + terminal side of the fuse block and one lead on a known good ground).
With SW1 open and the DMM leads across both fuse terminals, check for voltage.
voltage; short is between fuse block and SW1 (point A).
SGI847-A
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-33
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Revision: 2007 April2007 M35/M45
no voltage; short is further down the circuit than SW1.
With SW1 closed, relay and solenoid disconnected and the DMM leads across both fuse terminals, check
for voltage.
voltage; short is between SW1 and the relay (point B).
no voltage; short is further down the circuit than the relay.
With SW1 closed, relay contacts jumped with fused jumper wire check for voltage.
voltage; short is down the circuit of the relay or between the relay and the disconnected solenoid (point C).
no voltage; retrace steps and check power to fuse block.
Ground Inspection
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
Remove the ground bolt or screw.
Inspect all mating surfaces for tarnish, dirt, rust, etc.
Clean as required to assure good contact.
Reinstall bolt or screw securely.
Inspect for “add-on” accessories which may be interfering with the ground circuit.
If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to “Ground Distribution” in PG section.
Voltage Drop Tests
Voltage drop tests are often used to find components or circuits which have excessive resistance. A voltage
drop in a circuit is caused by a resistance when the circuit is in operation.
Check the wire in the illustration. When measuring resistance with DMM, contact by a single strand of wire will
give reading of 0 ohms. This would indicate a good circuit. When the circuit operates, this single strand of wire
is not able to carry the current. The single strand will have a high resistance to the current. This will be picked
up as a slight voltage drop.
Unwanted resistance can be caused by many situations as follows:
Undersized wiring (single strand example)
Corrosion on switch contacts
Loose wire connections or splices.
SGI853
REAR WINDOW DEFOGGER
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REAR WINDOW DEFOGGERPFP:25350
Component Parts and Harness Connector LocationNIS0022G
System DescriptionNIS0022H
The rear window defogger system is controlled by BCM and IPDM E/R.
The rear window defogger operates only for approximately 15 minutes.
Power is at all times supplied
through 20A fuse [No. 75, located in the IPDM E/R]
to rear window defogger relay terminals 6,
through 20A fuse [No. 80, located in the IPDM E/R]
to rear window defogger relay terminals 3,
through 15A fuse [No. 37, located in the fuse and fusible link box
to multi-function switch terminal 1,
PIIB6098E
1. Fuse block (J/B) 2. Fuse and fusible link box 3. Fuse block (in IPDM E/R)
4. IPDM E/R E4, E8, E9 5. BCM M1, M2 6.Rear window defogger switch (in
multi function switch) M69
7. Rear window defogger relay E36 8.a : Rear window defogger B604,B701
b : Condenser B49
GW-72
REAR WINDOW DEFOGGER
Revision: 2007 April2007 M35/M45
through 50A fusible link (letter F , located in the fuse and fusible link box)
to BCM terminal 55,
through 10A fuse [No. 21, located in the fuse block (J/B)]
to BCM terminal 42.
With the ignition switch turned to ON or START position,
Power is supplied
through 15A fuse [No. 1, located in the fuse block (J/B)]
to BCM terminal 38.
through 10A fuse [No. 12, located in the fuse block (J/B)]
to rear window defogger relay terminal 1.
With the ignition switch turned to ACC or ON position,
through 10A fuse [No. 6, located in the fuse block (J/B)]
to multi-function switch terminal 2.
Ground is supplied
to BCM terminal 52
through body grounds M16 and M70,
to multi-function switch terminal 14
through body grounds M16 and M70,
to IPDM E/R terminals 38 and 51
through body grounds E22 and E43.
When rear window defogger switch in multi-function switch is turned to ON.
Then multi-function switch recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signals to AV control unit (without navigation system) or NAVI con-
trol unit (with navigation system) via AV line.
When AV control unit (without navigation system) or NAVI control unit (with navigation system) receives rear
window defogger switch signals, and display on the screen.
Then AV control unit (without navigation system) or NAVI control unit (with navigation system) recognizes that
rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signal to BCM via DATA LINE (CAN H, CAN L).
Then BCM recognizes that rear window defogger switch signal.
Then it sends rear window defogger request signal to IPDM E/R via DATA LINE (CAN H, CAN L).
When IPDM E/R receives rear window defogger switch signals,
Ground is supplied
to rear window defogger relay terminal 2
through IPDM E/R terminal 57
through IPDM E/R terminal 51
through body grounds E22 and E43.
And then rear window defogger relay is energized.
When rear window defogger relay is turned ON, signals are transmitted.
through rear window defogger relay terminals 5 and 7
through condenser terminal 1
to rear window defogger terminal 1
Rear window defogger terminal 2 is grounded through grounds B702.
With power and ground supplied, rear window defogger filaments heat and defog the rear window.
When rear window defogger relay is turned to ON,
Power is supplied
through rear window defogger relay terminals 5 and 7
through fuse block (J/B) terminal 2C
through 10A fuse [No. 8, located in the fuse block (J/B)] and
through fuse block (J/B) terminal 5B
to door mirror (LH and RH) terminal 4.
Door mirror (LH and RH) terminal 8 is grounded through body grounds M16 and M70.
GW-80
REAR WINDOW DEFOGGER
Revision: 2007 April2007 M35/M45
Terminal and Reference Value for BCMNIS0022M
Terminal and Reference Value for IPDM E/RNIS0022N
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nalWire
colorItemSignal
Input/
OutputConditionVoltage (V)
(Approx.)
38 W Ignition switch ON or START Input Ignition switch (ON or START position) Battery voltage
39 L CAN− HInput/
Output——
40 P CAN− LInput/
Output——
42 P Power source (Fuse) Input — Battery voltage
52 B Ground — — 0
55 W Power source (Fusible link) Input — Battery voltage
Te r m i -
nalWire
colorItemSignal
Input/
OutputConditionVoltage (V)
(Approx.)
5 W Battery power supply Output — Battery voltage
6 R Battery power supply Output — Battery voltage
38 B Ground (Power) — — 0
49 L CAN− HInput/
Output——
50 P CAN− LInput/
Output——
51 B Ground (Signal) — — 0
57 GRear window defogger relay
control signalInputWhen rear window defogger switch is ON. 0
When rear window defogger switch is OFF. Battery voltage
GW-84
REAR WINDOW DEFOGGER
Revision: 2007 April2007 M35/M45
Check Rear Window Defogger Switch Circuit NIS0022S
1. CHECK REAR WINDOW DEFOGGER SWITCH OPERATION
With CONSULT-II
Check (“REAR DEF SW”, “IGN ON SW”) in DATA MONITOR mode with CONSULT-II.
OK or NG
OK >> Rear window defogger switch is OK.
NG >> GO TO 2.
2. CHECK AV LINE
Check AV line. Refer to AV- 2 4 9
(with navigation system), AV- 1 0 8 (without navigation system).
OK or NG
OK >> Check the condition of harness and connector.
NG >> The diagnosis is continued.
Check Rear Window Defogger Power Supply Circuit NIS0022T
1. CHECK FUSE
Check 10A fuse [No.12, located in the fuse block (J/B)]
Check 20A fuse (No.75, located in the IPDM E/R)
Check 20A fuse (No.80, located in the IPDM E/R)
NOTE:
Refer to GW-71, "
Component Parts and Harness Connector Location" .
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown out, be sure to eliminate cause of malfunction before installing new fuse, refer to
PG-3, "
POWER SUPPLY ROUTING CIRCUIT" .
2. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Remove rear window defogger relay.
3. Turn ignition switch ON.
4. Check voltage between rear window defogger relay connector and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness between fuse block (J/B) and rear window defogger relay.When rear window defogger switch is turned to ON
REAR DEF SW : ON
When ignition switch is turned to ON
IGN ON SW : ON
PIIA2373E
Terminals
Voltage (V)
(Approx.) (+)
(–) Rear window
defogger relay
connectorTerminal
E361
Ground Battery voltage 3
6
PIIB5994E
REAR WINDOW DEFOGGER
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3. CHECK REAR WINDOW DEFOGGER RELAY
Check rear window defogger relay.
OK or NG
OK >> GO TO 4.
NG >> Replace rear window defogger relay.
4. CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Install rear window defogger relay.
3. Turn ignition switch ON.
4. Check voltage between IPDM E/R connector and ground.
OK or NG
OK >> Rear window defogger power supply circuit is OK.
NG >> GO TO 5.
5. CHECK HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and rear window defogger relay.
3. Check continuity between IPDM E/R connector and rear window defogger relay connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness.
Terminal
Condition Continuity
Rear window
defogger relay
3512V direct current supply between termi-
nals 1 and 2.Ye s
No current supply No
6712V direct current supply between termi-
nals 1 and 2.Ye s
No current supply No
SEC202B
Terminals
Condition of
rear window
defogger switchVoltage (V)
(Approx.) (+)
(–)
IPDM E/R
connectorTerminal
E9 57 GroundON (pressed) 0
OFF Battery voltage
PIIB5982E
AB
Continuity
IPDM E/R
connectorTerminalRear window
defogger relay
connectorTerminal
E9 57 E36 2 Yes
PIIB5983E
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REAR WINDOW DEFOGGER
Revision: 2007 April2007 M35/M45
6. CHECK REAR WINDOW DEFOGGER RELAY OUTPUT SIGNAL
1. Connect IPDM E/R connector and rear window defogger relay.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R connector and ground.
OK or NG
OK >> Check condition of harness and connector.
NG >> Replace IPDM E/R.
Check Rear Window Defogger Circuit NIS0022U
1. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between rear window defogger connector and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear window defogger connector.
3. Check continuity between rear window defogger connector and ground.
OK or NG
OK >> Check filament. Refer to GW-92, "Check Filament"
If filament is OK, check condition of harness and con-
nector.
If filament is NG, repair filament.
NG >> Repair or replace harness between rear window defog-
ger and ground.
Terminals
Voltage (V)
(Approx.) (+)
(–)
IPDM E/R
connectorTerminal
E9 57 Ground Battery voltage
PIIB5982E
Te r m i n a l s
Condition of
rear window
defogger switchVoltage (V)
(Approx.) (+)
(–) Rear window
defogger
connectorTerminal
B604 1 GroundON Battery voltage
OFF 0
PIIB5984E
Rear window
defogger
connectorTerminal
GroundContinuity
B701 2 Yes
PIIB5985E