1999 TOYOTA AVENSIS sensor

IN0253
WRONG CORRECT
IN0252
WRONG CORRECT
IN0002
Example IN–6
– INTRODUCTIONREPAIR INSTRUCTIONS
(2) After the vehicle is jacked up, be sure to support it
on stands. It is extremely dangerous to do any work
on a vehicle raised on a jack alone, even for a small
job that can be finished quickly.
(l) Observe the following precautions to avoid damage to the
following parts:
(1) Do not open the cover or case of the ECU unless
absolutely necessary. (If the IC terminals are
touched, the IC may be destroyed by static electric-
ity.)
(2) To disconnect vacuum hoses, pull off the end, not
the middle of the hose.
(3) To pull apart electrical connectors, pull on the con-
nector itself, not the wires.
(4) Be careful not to drop electrical components, such
as sensors or relays. If they are dropped on a hard
floor, they should be replaced and not reused.
(5) When steam cleaning an engine, protect the elec-
tronic components, air filter and emission–related
components from water.
(6) Never use an impact wrench to remove or install
temperature switches or temperature sensors.
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose
onto a connector that is too large. Use a step–down
adapter for adjustment. Once the hose has been
stretched, it may leak air.
(m) Installation and removal of vacuum hose:
(1) When disconnecting vacuum hoses, use tags to
identify where they should be reconnected to.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.
(n) Unless otherwise stated, all resistance is measured at an
ambient temperature of 20
C (68
F). Because the resis-
tance may be outside specifications if measured at high
temperatures immediately after the vehicle has been run-
ning, measurement should be made when the engine has
cooled down.

R11910Match marks
IN–10
– INTRODUCTIONFOR ALL OF VEHICLES
(3) Even in cases of a minor collision where the SRS
does not deploy, the steering wheel pad (See Pub.
No. RM599E, page RS–15), front passenger airbag
assembly (See Pub. No. RM599E, page RS–28),
side airbag assemblies (See page RS–11), curtain
shield airbag assemblies (See page RS–25) and
seat belt pretensioners (See Pub. No. RM599E,
page BO–152) should be inspected.
(4) Never use SRS parts from another vehicle. When
replacing parts, replace them with new parts.
(5) Before repairs, remove the airbag sensor if shocks
are likely to be applied to the sensor during repairs.
(6) Never disassemble and repair the airbag sensor as-
sembly, side airbag sensor assembly, steering
wheel pad, front passenger airbag, side airbag or
seat belt pretensioner in order to reuse them.
(7) If the airbag sensor assembly, side airbag sensor
assembly, steering wheel pad, front passenger air-
bag, side airbag or seat belt pretensioner have
been dropped, or if there are cracks, dents or other
defects in the case, bracket or connector, replace
them with new ones.
(8) Do not directly expose the airbag sensor assembly,
side airbag sensor assembly, steering wheel pad,
front passenger airbag, side airbag or seat belt pre-
tensioner to hot air or flames.
(9) Use a volt/ohmmeter with high impedance (10 kΩ/V
minimum) for troubleshooting of the electrical cir-
cuit.
(10) Information labels are attached to the periphery of
the SRS components. Follow the instructions on the
notices.
(11) After work on the supplemental restraint system is
completed, check the SRS warning light (See Pub.
No. RM599E, page DI–152).
(c) SPIRAL CABLE (in Combination Switch)
The steering wheel must be fitted correctly to the steering
column with the spiral cable at the neutral position, other-
wise cable disconnection and other troubles may result.
Refer to Pub. No. RM599E, page SR–18 of this manual
concerning correct steering wheel installation.

– INTRODUCTIONFOR ALL OF VEHICLES
IN–15
(h) SEAT BELT PRETENSIONER
(1) Never measure the resistance of the seat belt pre-
tensioner. (This may cause the pretensioner oper-
ates, which is very dangerous.)
(2) Oil or water should not be put on the front seat outer
belt and the front seat outer belt should not be
cleaned with detergents of any kind.
(3) Store the front seat outer belt where the ambient
temperature remains below 80
C (176
F), without
high humidity and away from electrical noise.
(4) When using electric welding, first disconnect the
connector (yellow color and 2 pins) installed at the
center pillar lower garnish before starting work.
(5) When disposing of a vehicle or a front seat outer
belt alone, the seat belt pretensioner should be acti-
vated before disposal (See Pub. No. RM599E,
page BO–153). Perform the operation in a safe
place away from electrical noise.
(i) AIRBAG SENSOR ASSEMBLY
(1) Never reuse the airbag sensor assembly involved
in a collision when the SRS has deployed.
(2) The connectors to the airbag sensor assembly
should be connected or disconnected with the sen-
sor mounted on the floor. If the connectors are con-
nected or disconnected while the airbag sensor as-
sembly is not mounted to the floor, it could cause
undesired ignition of the supplemental restraint sys-
tem.
(3) Work must be started after 90 seconds from the
time the ignition switch is turned to the ”LOCK” posi-
tion and the negative (–) terminal cable is discon-
nected from the battery, even if only loosing the set
bolts of the airbag sensor assembly.
(j) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the instrument
panel wire harness and the cowl wire harness assembly
and floor wire harness assembly. The wires for the SRS
wire harness are encased in a yellow corrugated tube. All
the connectors for the system are also a standard yellow
color. If the SRS wire harness becomes disconnected or
the connector becomes broken due to an accident, etc.,
repair or replace it as shown on Pub. No. RM599E, page
RS–65.

IN–16
– INTRODUCTIONFOR ALL OF VEHICLES
2. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off and prolonged braking.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
3. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two–way radios and cellular telephones, observe
the following precautions.
(a) Install the antenna as far as possible away from the ECU and sensors of the vehicle’s electronic sys-
tem.
(b) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the vehicle’s
electronic systems. For details about ECU and sensors locations, refer to the section on the applicable
component.
(c) Do not wind the antenna feeder together with the other wiring as much as possible, also avoid running
the antenna feeder parallel with other wire harnesses.
(d) Check that the antenna and feeder are correctly adjusted.
(e) Do not install powerful mobile communications system.
4. FOR USING HAND–HELD TESTER
CAUTION:
Observe the following items for safety reasons:
Before using the hand–held tester, the hand–held tester’s operator manual should be read thor-
oughly.
Be sure to route all cables securely when driving with the hand–held tester connected to the
vehicle. (i.e. Keep cables away from feet, pedals, steering wheel and shift lever.)
Two persons are required when test driving with the hand–held tester, one person to drive the
vehicle and the other person to operate the hand–held tester.

DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE
Diagnostic Trouble
Code Check (Make a
note of and then clear)Confirmation
of SymptomsDiagnostic Trouble
Code CheckProblem Condition
Diagnostic Trouble
Code DisplayProblem symptoms
existSame diagnostic
trouble code is
displayedProblem is still occurring in the diagnostic
circuit
Normal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)
No problem
symptoms existThe problem occurred in the diagnostic
circuit in the past
Normal Code DisplayProblem symptoms
existNormal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
No problem
symptoms existNormal code is
displayedThe problem occurred in a place other
than in the diagnostic circuit in the past
– INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN–21
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the AVENSIS/ CORONA fulfills various functions. The first function is the Diagnos-
tic Trouble Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU
memory at the time of occurrence, to be output by the technician during troubleshooting. Another function
is the Input Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the AVENSIS/
CORONA.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Other Diagnosis
Function
Supplemental Restraint System
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table below. If this is not done, it may, depending on the case, result in unnecessary troubleshooting
for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent
to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble
code check.

V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR1
Slightly shake the connector vertically and horizontally.
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.
Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check that the mal-
function occurs.Shake Slightly
Swing Slightly
Vibrate Slightly
HINT:
Applying strong vibration to relays may result in open relays.
– INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN–23
3. SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases,
a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and
environment in which the problem occurred in the customer’s vehicle. No matter how much experience a
technician has, or how skilled he or she may be, if he or she proceeds to troubleshoot without confirming
the problem symptoms he or she will tend to overlook something important in the repair operation and make
a wrong guess somewhere, which will only lead to a standstill. For example, for a problem which only occurs
when the engine is cold, or for a problem which occurs due to vibration caused by the road during driving,
etc., the problem can never be determined so long as the symptoms are confirmed with the engine hot condi-
tion or the vehicle at a standstill. Since vibration, heat or water penetration (moisture) is likely cause for prob-
lem which is difficult to reproduce, the symptom simulation tests introduced here are effective measures in
that the external causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should of course be confirmed, but the problem area
or parts must also be found out. To do this, narrow down the possible problem circuits according to the symp-
toms before starting this test and connect a tester beforehand. After that, carry out the symptom simulation
test, judging whether the circuit being tested is defective or normal and also confirming the problem symp-
toms at the same time. Refer to the problem symptoms table for each system to narrow down the possible
causes of the symptom.

Detection Item DTC No.
(See page)Trouble AreaSRS
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, check the circuit listed for that code in the table
below. (Proceed to the page given for that circuit).
Warming Light
ON
ON
ON
ON
ON
ON
ON
DTC No.
Indicates the diagnostic trouble code.
Page or Instructions
Indicates the page where the inspection procedure
for each circuit is to be found, or gives instructions
for checking and repairs. 

Detection Item
Indicates the system of the problem or
contents of the problem. Trouble Area
Indicates the suspect area of the
problem. 
11
(DI–165)
12
(DI–170)
13
(DI–174)
14
(DI–178)
15
(DI–178)
16
airbag sensor assembly malfunction Front airbag sensor assembly (RH)
malfunction Short in D squib circuit (to ground)
Short in D squib circuit (to B)
Short in D squib circuit
Open in D squib circuit
Front airbag sensor assembly (LH)
malfunction Steering wheel pad (squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
 Front airbag sensor assembly (RH)
 Wire harness
 Front airbag sensor assembly (LH)
 Wire harness  Steering wheel pad (squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
 Steering wheel pad (squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
 Steering wheel pad (squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
Airbag sensor assembly
 Front passenger airbag sensor assembly (squib)
 Airbag sensor assembly Short in P squib circuit (to ground)ON
– INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN–25
4. DIAGNOSTIC TROUBLE CODE CHART
The inspection procedure is shown in the table below. This table permits efficient and accurate troubleshoot-
ing using the diagnostic trouble codes displayed in the diagnostic trouble code check. Proceed with trouble-
shooting in accordance with the inspection procedure given in the diagnostic chart corresponding to the
diagnostic trouble codes displayed. The Supplemental Restraint System diagnostic trouble code chart is
shown below as an example.



B02407
WIRING DIAGRAM
DTC 13 Short in D Squib Circuit
CIRCUIT DESCRIPTION
The D squib circuit consists of the airbag sensor assembly, spiral cable and steering wheel pad.
It causes the airbag to deploy when the airbag deployment conditions are satisfied.
For details of the function of each components,see OPERATION on page RS–2.
DTC 13 is recorded when a short is detected in the D squib circuit.
DTC No.DTC Detecting Condition
Trouble Area
Short circuit between D wire harness and D wire harness of squib
D squib malfunction
Spiral cable malfunction
Airbag sensor assembly malfunctionSteering wheel pad (D squib)
Spiral cable
Airbag sensor assembly
Wire harness
 Diagnostic Trouble Code No. and Detection Item
Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained. 
Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem. 
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe. 
Spiral
Cable
G–R
G–Y 1
27
6D+
D–
A15
A15
D SquibAirbag Sensor
Assembly
13
– INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN–27
6. CIRCUIT INSPECTION
How to read and use each page is shown below.