HOW TO READ THE WIRING DIAGRAMS -How to Read Circuit DiagramsA-4
HOW TO READ CIRCUIT DIAGRAMS
The circuit of each system from fuse (or fusible link) to earth is shown. The power supply is shown
at the top and the earth at the bottom to facilitate understanding of the current flow.
Indicates the power supply in the control
unit. If no voltage is displayed, this
indicates SYSTEM voltage.
Indicates power take out.
Indicates connector No. The same
No. as in the wiring harness diagram
is used.
Connector numbers enclosed by
frame are indicated with the
connector symbols at the lower part
of the page.
Connector numbers not enclosed by
a frame indicate components which
are integrated with the harness.
Indicates harness junction point No. for
another system. It corresponds to the
junction point No. indicated on the
destination system circuit diagram.
Indicates the circuit name to be
connected. The arrow indicates the
current flow direction.
An “X” at the end of a connector No.
indicates that the connector is connected
to a centralized junction that is shown
in the section “CENTRALIZED JUNC-
TION”.
Indicates the operating condi-
tions of the engine coolant
temperature switch, etc.
Indicates the connector symbol.
Connectors in the circuit diagram are
indicated in numerical order.
Indicates shield wire.
Indicates that terminal is connected via
a plate in the relay box.
Each circuit diagram consists of
block(s). The blocks are divided by
page number.
Indicates that the diagram continues
at
Awhich belongs to the block
in the same circuit.2
Indicate that the current flows
from down to up. Bi-directional
arrows indicate that the
direction of current flow
changes when communication
is in progress.
CIRCUIT DIAGRAMSB-55
Front sideRear side
To instrument
panel wiring
harness
Power
window
relay
Fuel pump
relay (1)
Fuel pump
relay (2)
Rear fog
lamp relay
To roof
wiring
harness
To instrument
panel wiring
harness
Blower
relay
Defogger
relay
Fuse box
(multi-purpose
fuse No.1 to 20)
To floor
wiring
harness
ETACS-ECU
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles
C-208C-210
C-211C-209C-225
C-213
C-223
C-224C-215C-214C-222
C-221
C-220
C-219
C-218C-216*1
C-217*2
1 23456
789
10 11 12
13 14 15 16 17 1819
20
C-226
Inter cooler
water spray
relay
CIRCUIT DIAGRAMSB-68
CENTRALIZED JUNCTION
FUSIBLE LINK
No.CircuitTypeHousing colourRated capacity
(A)
1Multi-purpoes fuses No. 15, 16, 17, 19, 20Screwed typeYellow60
2Cooling circuit and manual air conditioner circuitConnector typeRed50
3ABS circuitConnector typeYellow60
4Ignition switchConnector typeGreen40
5Power window circuitConnector typePink30
6Battery, fusible links No. 1, 2, 3, 4 and 5,
dedicated fuses No. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
18, starting system, front-ECUScrewed type-100
7ACDScrewed type-60
(Relay box in engine compartment)
Front of vehicle
(Connected directly to battery positive (+) terminal)
Front of vehicle
1
234
5
6 7
6
SWS -Special Tools/Troubleshooting54B-2
SPECIAL TOOLS
ToolNumberNameUse
MB991502MUT-II subassem-
blyFor SWS inspections (diagnosis code display
and input signal check by MUT-II)
MB991529Diagnosis code
check harnessFor checking input signals by voltmeter
A
B
C
D
MB991223
A: MB991219
B: MB991220
C: MB991221
D: MB991222Harness set
A: Test harness
B: LED harness
C: LED harness
adapter
D: ProbeFor checking voltage (continuity and value) at
harnesses and connectors
A: For checking connector pin contact voltage
B: For checking power supply circuits
C: For checking power supply circuits
D: For connection to commercially available
testers
TROUBLESHOOTING
BEFORE COMMENCING TROUBLESHOOTING
Before starting troubleshooting, check the following two points to ensure there are no defects.
DCheck the state of the connector couplings to the ETACS-ECU and junction box.
DCheck that the fuses and fusible links relating to all systems are not fused.
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points.
DIAGNOSTIC FUNCTIONS
READING DIAGNOSIS CODES
Read the diagnosis codes using MUT-II. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points.)
NOTE
1. Connect MUT-II to the 16-pin diagnosis connector (black).
2. The diagnosis code cannot be read when there is an ETACS-ECU fault or when the power is first
turned ON (voltage rising). In this case, refer to “No Communication with MUT-II” (P. 54B-10) on
Fault Symptom Inspection Procedure, and perform troubleshooting.
