2005 TOYOTA AVENSIS diagnostic

± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±25
AVENSIS REPAIR MANUAL (RM1018E)
SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE
HINT:

The diagnostic system in AVENSIS has various functions. The first function is the Diagnostic Trouble
Code (DTC) Check, in which a malfunction in the signal circuits to the ECU is stored in code form in
the ECU memory. 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, it is possible to quickly narrow
down potential problem areas and troubleshooting can be performed effectively. The diagnostic func-
tions are incorporated in the following systems in the AVENSIS.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
SFI System (1AZ±FE/1AZ±FSE, 1ZZ±FE/3ZZ±FE)

(with Check Mode)


ECD System (1CD±FTV)

(with Check Mode)


ABS with EBD System



ABS with EBD & BA & TRC & VSC System



Electronically Controlled Automatic Transmission [ECT]

(with Check Mode)

Air Conditioning System


Supplemental Restraint System

Audio System

Power Door Lock Control System


Wireless Door Lock Control System

Key Reminder Warning System

Engine Immobiliser System


Theft Deterrent System


Multiplex Communication System

Cruise Control System



In the DTC check, it is very important to determine whether the problem indicated by the DTC is still
occurring or has occurred in the past but returned to normal at present. In addition during the problem
symptom check, it a check must be made on whether the malfunction indicated by the DTC is directly
related to the problem symptom or not. For this reason, the DTC should be checked before and after
symptom confirmation to determine the current conditions. If this is not done, it may, depending on the
case, result in unnecessary troubleshooting for systems that are operating normally. This would make
more difficult to detect the problem area or to try to repair irrelevant areas. Therefore, always follow
the procedures in the correct order and perform the DTC check.

A flow chart showing how to proceed with troubleshooting using the diagnostic trouble code (DTC)
check is shown the this page. This flow chart shows how to utilize the DTC check effectively. Then,
by carefully checking the results, this chart indicates how to proceed either to the DTC troubleshooting
or to the troubleshooting of the problem symptoms table.
1 DTC check
2 Make a note of DTCs displayed and then clear the memory
3 Symptom confirmation

01±26±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)

Symptoms exist
No symptoms exist
a Go to step 5
b
4 Simulation test using the symptom simulation methods
5 DTC check

DTC displayed
Normal code displayed
a Troubleshooting of problem indicated by DTC
b
6 Symptom confirmation

No symptoms exist
Symptoms exist
If a DTC is displayed in the initial DTC check, it indicates that
a trouble may have occurred in a wire harness or connector in
that circuit in the past. Therefore, check the wire harness and
connectors (See page 01±32). a System normal
b
Troubleshooting of each problem symptom
The problem is still occurring in a place other than the diagnostic circ\
uit (The DTC displayed first is either
for a past problem or a secondary problem).

Detection Item
Indicates the system or details of the
problem. Trouble Area
Indicates the suspect areas of
the problem.
Detection Item
DTC No.
(See page)
Trouble Area
SRS


Steering wheel pad (squib)

Spiral cable

Airbag sensor assembly

Wire harness
B0103/12
(05±132) B0102/11
(05±128)
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, check the circuit for that code liste\
d in the table
below (Proceed to the page given for that circuit).

Short in D squib circuit

Open in D squib circuit
B0101/14
(05±124)

Short in D squib circuit (to ground)

Short in D squib circuit (to B+)
Warning Light
ON
ON
ON
ON


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
B0105/53
(05±136) ON

Airbag sensor assembly

Wire harness
B0106/54

Open in P squib circuit

Airbag sensor assembly

Wire harness


Short in P squib circuit (to Ground) ON
ON
B0100/13
(05±119)

Short in P squib circuit

Front passenger airbag assembly (squib)

Airbag sensor assembly

Wire harness

Front passenger airbag assembly (squib)

Front passenger airbag assembly (squib)
Page or Instructions
Indicates the page where the inspection proce-
dures for each circuit is to be found, or gives
instructions for checking and repairs.


DTC No.
Indicates the diagnostic trouble code.



±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±29
AVENSIS REPAIR MANUAL (RM1018E)
DIAGNOSTIC TROUBLE CODE CHART
The inspection procedures are shown in the table below. This table allows efficient and accurate trouble-
shooting using the diagnostic trouble codes displayed in the diagnostic trouble code chart. Proceed with
troubleshooting in accordance with the inspection procedures listed in the diagnostic c\
hart corresponding
to the diagnostic trouble codes displayed. The diagnostic trouble code chart for the Supplemental Restraint
System is shown below as an example.

01±30±
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
AVENSIS REPAIR MANUAL (RM1018E)
PROBLEM SYMPTOMS TABLE
The suspected circuits or parts for each problem symptom are shown in the t\
able below. Use this table to
troubleshoot the problem when a Normal code is displayed in the diagnostic trouble c\
ode chart but the prob-
lem is still occurring. Numbers in the table indicate the order in which\
the circuits or parts should be checked.
HINT:
When the problem is not detected by the diagnostic system even though the pr\
oblem symptom is present,
it may be that the problem is occurring outside the detection range of t\
he diagnostic system.
Symptom Suspected AreaSee page
1. With the ignition switch in ACC or ON position, the SRS warning
light sometimes lights up after approx. 6 seconds have elapsed.
2. SRS warning light is always lit up even when ignition switch is
in the LOCK position
1. With the ignition switch in the ACC or ON position, the SRS
warning light does not light up.
PROBLEM SYMPTOMS TABLE
1. DTC is not displayed. 05±187 05±183
Problem SymptomPage
Indicates the page where the flow chart for each circuit
is located.
Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.
Circuit or Part Name
Indicates the circuit or part which needs to be checked.
Proceed with troubleshooting of each circuit in the table below.
1. SRS warning light circuit
(Always lights up when ignition switch is in
LOCK position.)
1. SRS warning light circuit
(Does not light up when ignition switch is turned
to ACC or ON.)
1. Tc terminal circuit
05±180





3. DTC is displayed without Tc and CG terminal connection. 2. SRS warning light is always lit up at the time of DTC check
procedure.

SFI
SFISFI
SFISFI
SFI
D25842

Circuit Description
The major role and, operation of the circuit
and its component parts are explained.

Diagnostic Trouble Code No. and Detection Item

Indicates the diagnostic trouble codes, diagnostic
trouble code settings and suspect areas for a
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, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.
Inspection Procedures
Use the inspection procedures to determine
if the circuit is normal or abnormal. If it is ab-
normal, use it to determine whether the prob-
lem is located in the sensors, actuators, wire
harness or ECU.

Indicates the condition of the connector of the ECU
during the check.


Connections of tester are
indicated by (+), (±) after
terminals name.
Connector being checked
is connected.Connector being checked
is disconnected.
For inspection of connector
with body ground, there is
nothing about the body
ground written down.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS01±31
AVENSIS REPAIR MANUAL (RM1018E)
CIRCUIT INSPECTION
How to read and use each page is shown below.

A75348  



AB Temprature SensorB+
Power Transistor
Platinum Hot Wire
Output
Voltage
Platinum Hot Wire
Temprature Sensor 05±24
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0100 MASS AIR FLOW CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
The mass air flow meter uses a platinum hot wire. The hot wire air flow meter consists of a platinum hot wire,
temprature sensor and a control circuit installed in a plastic housing. The hot wire air flow meter works on
the principle that the hot wire and temprature sensor located in the intake air bypass of the housing detect
any changes in the intake air temperature.
The hot wire is maintained at the set temperature by controlling the current flow through the hot wire. This
current flow is then measured as the output voltage of the mass air flow meter.
The circuit is constructed so that the platinum hot wire and temprature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC NoDTC Detecting ConditionTrouble Area
P0100Open or short in mass air flow meter circuit with engine speed
less than 4,000 rpm for more than 3 sec.
Open or short in mass air flow meter circuit

Mass air flow meter

ECM
HINT:
After confirming DTC ºP0100º, use the hand±held tester to confirm the air flow ratio in the ºDIAGNOSIS /
OBD/MOBD / DATA LIST / ALLº.
Air Flow Value (gm/sec)Malfunction
Approx. 0.0
Mass air flow meter power source circuit open

VG circuit open or short
271.0 or more
EVG circuit open
05C68±01

A79052
A6
Mass Air Flow MeterECM
1
3 EVG
VG
L±Y
G
2
B±R 12
EA1 32
E12
24
E12
B±R
From
Terminal 2 of
EFI No.1 Fuse
(See Page 05±124)
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±25
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using \f \b\f\f
 Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, it is useful for determi\
ning whether the vehicle was running
or stopped, the engine was warmed up or not, the air±fuel ratio was lea\
n or rich, etc. at the time of the mal-
function.
1READ VALUE OF HAND±HELD TESTER(MASS AIR FLOW RATE)
(a)Connect the hand±held tester to the DLC3.
(b)Start the engine.
(c)Read air flow rate on the hand±held tester.
(d)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALL / MAFº and read its value displayed on the hand±held tester.
Result:
Air flow rate (gm/sec)Proceed to
0.0A
271.0 or moreB
1 less than Mass Air Flow Rate less than 270.0 or more (*1)C
*1: The value must be changed when the throttle valve is opend or closed.
BGo to step 6
CCHECK FOR INTERMITTENT PROBLEMS(See Page 05±5)
A

A54396
Wire Harness SideMass Air Flow Meter Connector
+B
A6
A18294
VG (+)EVG (±)
ECM Connector E12
05±26
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
2INSPECT MASS AIR FLOW METER(POWER SORUCE VOLTAGE)
(a)Disconnect the mass air flow meter connector.
(b)Turn the ignition switch ON.
(c)Measure the voltage between the terminal of the wire har- ness side connector and the body ground.
Standard:
Symbols (Terminal No.)Specified condition
+B (A6±1) ± Body ground9 to 14 V
NGGo to step 5
OK
3INSPECT ECM
(a)Turn the ignition switch ON.
(b)Measure the voltage between the terminals of the E12 ECM connector.
HINT:
The shift position should be P or N and the A/C switch should
be turned OFF. Standard:
Symbols (Terminal No.)ConditionSpecified condition
VG (E12±24) ±
EVG (E12±32)Engine is idling0.5 to 3.0 V
OKCHECK AND REPLACE ECM (See page 01±32)
NG