1996 TOYOTA RAV4 Electrical

44
H POWER SOURCE (Current Flow Chart)
The chart below shows the route by which current flows from the battery to each electrical source (Fusible Link,
Circuit Breaker, Fuse, etc.) and other parts.
The next page and following pages show the parts to which each electrical source outputs current.
* These are the page numbers of the first page on which
the related system is shown.
The part indicated is located somewhere in the system,
not necessarily on the page indicated here.
[LOCATION]: J/B No. 1 (See page 20): J/B No. 4 (See page 23)
: R/B No. 6 (See page 25): Fusible Link Block (F7 on See page 28)

64
ENGINE CONTROL
THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND MAINTAINS OVERALL CONTROL OF THE ENGINE ETC. AN
OUTLINE OF ENGINE CONTROL IS GIVEN HERE.
1. INPUT SIGNALS
(1) ENGINE COOLANT TEMP. SENSOR SIGNAL SYSTEM
THE ENGINE COOLANT TEMP. SENSOR DETECTS THE ENGINE COOLANT TEMP. AND HAS A BUILT-IN THERMISTOR WITH A
RESISTANCE WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP. THUS THE ENGINE COOLANT TEMP. IS INPUT IN
THE FORM OF A CONTROL SIGNAL TO TERMINAL THW OF THE ENGINE CONTROL MODULE.
(2) INTAKE AIR TEMP. SIGNAL SYSTEM
THE INTAKE AIR TEMP. SENSOR DETECTS THE INTAKE AIR TEMP. , WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA
OF THE ENGINE CONTROL MODULE.
(3) OXYGEN SENSOR SIGNAL SYSTEM
THE OXYGEN SENSOR DETECTS THE OXYGEN DENSITY IN THE EXHAUST EMISSION WHICH IS INPUT AS A CONTROL SIGNAL
TO TERMINALS OX1 AND OX2 OF THE ENGINE CONTROL MODULE.
(4) THROTTLE SIGNAL SYSTEM
THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE, WHICH IS INPUT AS A CONTROL
SIGNAL TO TERMINAL VTA OF THE ENGINE CONTROL MODULE, OR WHEN THE VALVE IS FULLY CLOSED.
(5) VEHICLE SPEED CIRCUIT
THE VEHICLE SPEED IS DETECTED BY VEHICLE SPEED SENSOR INSTALLED IN THE TRANSMISSION AND THE SIGNAL IS INPUT
TO TERMINAL SPD OF THE ENGINE CONTROL MODULE VIA THE COMBINATION METER.
(6) PARK/NEUTRAL POSITION SW SIGNAL SYSTEM
THE PARK/NEUTRAL POSITION SW DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR NOT, AND INPUTS A CONTROL
SIGNAL TO TERMINAL NSW OF THE ENGINE CONTROL MODULE.
(7) A/C SW SIGNAL SYSTEM
THE OPERATING VOLTAGE OF THE A/C MAGNETIC CLUTCH IS DETECTED AND INPUT IN THE FORM OF A CONTROL SIGNAL TO
TERMINAL ACI OF THE ENGINE CONTROL MODULE.
(8) BATTERY SIGNAL SYSTEM
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE. WHEN THE IGNITION SW IS
TURNED TO ON, VOLTAGE FOR THE ENGINE CONTROL MODULE OPERATION IS APPLIED VIA THE EFI MAIN RELAY TO
TERMINAL +B OF THE ENGINE CONTROL MODULE.
(9) INTAKE AIR VOLUME SIGNAL SYSTEM
INTAKE AIR VOLUME IS DETECTED BY THE MANIFOLD ABSOLUTE PRESSURE SENSOR AND IS INPUT AS A CONTROL SIGNAL
TO TERMINAL PIN OF THE ENGINE CONTROL MODULE.
(10) STARTER SIGNAL SYSTEM
TO CONFIRM THAT THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL STA OF THE ENGINE CONTROL MODULE.
(11) ELECTRICAL LOAD SIGNAL SYSTEM
THE SIGNAL WHEN SYSTEMS SUCH AS THE REAR WINDOW DEFOGGER, HEADLIGHT, ETC. WHICH CAUSE A HIGH ELECTRICAL
BURDEN ARE ON IS INPUT TO TERMINAL ELS AS A CONTROL SIGNAL.
SYSTEM OUTLINE

65
2. CONTROL SYSTEM
*SFI
THE SFI SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS, WHICH ARE INPUT FROM EACH SENSOR (INPUT
SIGNALS (1) TO (11)). THE BEST FUEL INJECTION VOLUME IS DECIDED BASED ON THIS DATA AND THE PROGRAM MEMORIZED
BY THE ENGINE CONTROL MODULE, AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, AND #40 OF THE
ENGINE CONTROL MODULE TO OPERATE THE INJECTOR (INJECT THE FUEL). THE SFI SYSTEM PRODUCES CONTROL OF FUEL
INJECTION OPERATION BY THE ENGINE CONTROL MODULE IN RESPONSE TO THE DRIVING CONDITIONS.
*IDLE SPEED CONTROL SYSTEM
THE IDLE SPEED CONTROL SYSTEM INCREASES THE RPM AND PROVIDES IDLING STABILITY FOR FAST IDLE-UP WHEN THE
ENGINE IS COLD AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL LOAD, ETC. THE ENGINE CONTROL MODULE
EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS (1 TO 5, 11), OUTPUTS CURRENT TO TERMINAL ISCO AND ISCC,
AND CONTROLS THE IDLE AIR CONTROL VALVE.
*A/C CUT CONTROL SYSTEM
WHEN THE VEHICLE SUDDENLY ACCELERATES FROM LOW ENGINE SPEED, THIS SYSTEM CUTS OFF AIR CONDITIONING
OPERATION FOR A FIXED PERIOD OF TIME IN RESPONSE TO THE SPEED SENSOR, THROTTLE VALVE OPENING ANGLE AND
INTAKE MANIFOLD PRESSURE IN ORDER TO MAINTAIN ACCELERATION PERFORMANCE.
THE ENGINE CONTROL MODULE RECEIVES INPUT SIGNALS (4, 5 AND 9), AND INPUTS SIGNALS TO TERMINAL ACT.
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE SIGNAL SYSTEM, THE
MALFUNCTIONING SYSTEM IS RECORDED IN THE MEMORY. THE MALFUNCTIONING SYSTEM CAN THEN BE FOUND BY READING
THE DISPLAY (CODE) OF THE MALFUNCTION INDICATOR LAMP.
4. FAIL-SAFE SYSTEM
WHEN A MALFUNCTION OCCURS ON ANY SYSTEM, IF THERE IS A POSSIBILITY OF ENGINE THROUBLE BEING CAUSED BY
CONTINUED CONTROL BASED IN THE SIGNALS FROM THAT SYSTEM, THE FAIL-SAFE SYSTEM EITHER CONTROLS THE SYSTEM BY
USING DATA (STANDARD VALUES) RECORDED IN THE ENGINE CONTROL MODULE MEMORY OR ELSE STOPS THE ENGINE.

11 5
SRS
NOTICE: When inspecting or repairing the SRS, perform the operation in accordance with the following
precautionary instructions and the procedure and precautions in the Repair Manual for the applicable model
year.

Malfunction symptoms of the supplemental restraint system are difficult to confirm, so the diagnostic trouble
codes become the most important source of information when troubleshooting.
When troubleshooting the supplemental restraint system, always inspect the diagnostic trouble codes before
disconnecting the battery.

Work must be started after 90 seconds from the time the ignition SW is turned to the LOCKº position and the
negative (-) terminal cable is disconnected from the battery.
(The supplemental restraint system is equipped with a back-up power source so that if work is started within
90 seconds of disconnecting the negative (-) terminal cable of the battery, the SRS may be activated.)
When the negative (-) terminal cable is disconnected from the battery, the memory of the clock and audio
systems will be canceled. So before starting work, make a record of the contents memorized by each memory
system. When work is finished, reset the clock and audio system as before and adjust the clock.
To avoid erasing the memory of each memory system, never use a back-up power supply from outside the
vehicle.

When removing the steering wheel pad or handling a new steering wheel pad, keep the pad upper surface
facing upward. Also, lock the lock lever of the twin lock type connector at the rear of the pad and take care
not to damage the connector.
(Storing the pad with its metallic surface up may lead to a serious accident if the SRS inflates for some reason.)

Always store a removed or new front passenger airbag assembly with the airbag door facing up. Storing the
airbag assembly with the airbag door facing down could cause a serious accident if the airbag inflates.

Store the steering wheel pad where the ambient temperature remains below 935C (2005F), without high
humidity and away from electrical noise.

Never use SRS parts from another vehicle. When replacing parts, replace them with new parts.

Never disassemble and repair the steering wheel pad, front passenger airbag assembly, airbag sensor
assembly.

Before repairing the body, remove the airbag sensor if during repair shocks are likely to be applied to the
sensors due to vibration of the body or direct tapping with tools or other parts.

Do not reuse a steering wheel pad or front airbag sensors.
After evaluating whether the center airbag sensor assembly is damaged or not, decide whether or not to reuse
it. (See the Repair Manual for the method for evaluating the center airbag sensor assembly.)

When troubleshooting the supplemental restraint system, use a high-impedance (Min. 10kW/V) tester.

The wire harness of the supplemental restraint system is integrated with the instrument panel wire harness
assembly.
The vehicle wiring harness exclusively for the airbag system is distinguished by corrugated yellow tubing, as
are the connectors.

Do not measure the resistance of the airbag squibs.
(It is possible this will deploy the airbag and is very dangerous.)

If the wire harness used in the supplemental restraint system is damaged, replace the whole wire harness
assembly.

INFORMATION LABELS (NOTICES) are attached to the periphery of the SRS components. Follow the
instructions on the notices.

11 6
SRS
The supplemental restraint system has connectors which possess the functions described below:
1. SRS ACTIVATION PREVENTION MECHANISM
Each connector contains a short spring plate. When the
connector is disconnected, the short spring plate
automatically connects the power source and grounding
terminals of the squib to preclude a potential difference
between the terminals.
2. ELECTRICAL CONNECTION CHECK MECHANISM
This mechanism is designed to electrically check if
connectors are connected correctly and completely.
The electrical connection check mechanism is designed so
that the disconnection detection pin connects with the
diagnosis terminals when the connector housing lock is in
the locked position.

168
K OVERALL ELECTRICAL WIRING DIAGRAM

170
SYSTEM INDEX
1996 Model (Location No. 1 to 20)
K OVERALL ELECTRICAL WIRING DIAGRAM

K
1
234
1 RAV4 ELECTRICAL WIRING DIAGRAM
2ACC
IG 1
IG 2
ST2 AM1 4
6
8 7AM2
11 IG 1
10 IG1 7 EA1
12 IG 1 1D 9
2 2 2 2
22
22 1K 4
2 5
3 7
1D
8
1D
3
1D1
1F
9
1E
13
1H
8 EA12IG1 2IG2 1EA1
1A
2B
IG
B
B
A L
S
B
EA1E 81E1
1B 81C11
8 9
P
N
1
B
W WB
WWB-RBW-BW-BR-L B-O Y B-O
R- L B B-OW W
R-L R-L
W
B B
B-W B-R
B-W B-OB
B(
A/T)
B-R B-R
W
Power Source Starting Charging
S 2 B , S 3 A
G 1 A , G 2 B STARTER
GENERATOR1
3
1 2
13 21
42310
A11 4
40A
AM1
3 0 A M A IN NO . 1
20A AM2
5A ALT-S
100A ALT 80A MAIN
F 7
FUSIBLE LINK
BLO C K
BATTERY
J 1
JUNCTION
CONNECTOR
ST R ELAY
Radiator rightF 8
10A GAUGE
[FUSE BLOCK]F 8
7. 5A IGN
[FUSE BLOCK]
C11
CHARGE WARNING
LIGHT
[C OM B . M E TER ]
Y W W
B-Y
12 20 56I10
IGN ITIO N SW
1
W
1 (
M/T) B-W
B-WB(
A/T)
9 EA1
(
A/T)B
(
A/T)
B-W
From Engine Control Module
<2-2
From E ngine Control M odule
< 2-2 < 4-4 From E ngine
Control Module
<2-2
(
M/T)
123 1B G 2 BROWN A G 1GENERATOR
1 1A S 3 BLACK B S 2A
STARTER 6CA
BBJ10 A , J11 B
JUNCTION
CONNECTOR
B
(
A/T)
B
(
A/T)C C
C
To C ombin atio n
Meter< 18-3
J 5
JUN CTION
CONNECTOR 3A
6B 5B 2A 12
B-W
(
M/T)
B
(M/T)
(
A/T)
B- W(
M/T)
B- W
(
A/T)A
A
AJ 5
JUNCTION
CONNECTOR
C 8
CLUTCH
START SW
T o C om bina tion
M eter< 18- 3
(
2WD)
(
4WD)
(
2WD)
(
4WD) P 1 A , B
PARK/NEUTRAL
POSITION SW
AAAAAA
BBBCCC 123
4
5
67891
756234
8910 A (
2WD)
P 1GRAY B(4 WD ) P 1 G R AY
B J11 GRAY PARK/NEUTRAL POSITION SW
JUNCTION CONNECTOR
A J10 GRAY
B-W (
A/T)