sensor TOYOTA AVALON 2001 Service Repair Manual

V08423 Knock Sensor 1
GRECM
KNK
E1 12
E6
WIRING DIAGRAM
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.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detecting Condition Trouble Area
P0325No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more.
Open or short in knock sensor1 circuit

Knock sensor 1 (looseness)

ECM
If the ECM detects the above diagnosis conditions, it operates the fall safe function in which the corrective retard angle
value is set to the maximum value.

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.

IN-28
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
28 Author
: Date
:
2001 AVALON (RM808U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.

V08425
LOCK
KNK
E6 Connector
(a) Remove the glove compartment (See page SF-68).
(b) Disconnect the E6 connector of ECM.
INSPECTION PROCEDURE
Replace knock sensor. 1 Check continuity between terminal KNK of ECM connector and body ground.
OK:
Check knock sensor (See page SF-61).Measure resistance between terminal KNK of ECM connector
and body ground.
Resistance: 1 MW or higher
Connector being checked is connected.
Indicates the condition of the connector of ECU during the check.
PREPARATION:
CHECK:
2Go to step 3.
OK OK
NG

Indicates the position of the ignition switch during the check.
Check from the connector back side.
(with harness)
Ignition Switch LOCK (OFF)
Ignition Switch START
LOCKIgnition Switch ON
Ignition Switch ACC
STARTON
ACC



Indicates the place to check the voltage or resistance.

Indicates the connector position to checked, from the front or back side.
Connector being checked is disconnected. Check from the connector front side. (without harness)
In this case, care must be taken not to bend the terminals.
E6 Connector KNKWire Harness
E6 Connector KNK
A00255 AB0117
A00265
Inspection Procedure
Use the inspection procedure to determine if
the circuit is normal or abnormal, and, if it is
abnormal, use it to determine whether the
problem is located in the sensors, actuators,
wire harness or ECU.
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-29
29 Author
: Date
:
2001 AVALON (RM808U)

FI0048
FI0047
FI0046
IN05X-1 1
IN-30- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
30 Author
: Date
:
2001 AVALON (RM808U)
HOW TO USE THE DIAGNOSTIC
CHART AND INSPECTION
PROCEDURE
1. CONNECTOR CONNECTION AND TERMINAL IN-
SPECTION

For troubleshooting, diagnostic trouble code charts or
problem symptom table are provided for each circuit with
detailed inspection procedures on the following pages.

When all the component parts, wire harnesses and con-
nectors of each circuit except the ECU are found to be
normal in troubleshooting, then it is determined that the
problem is in the ECU. Accordingly, if diagnosis is per-
formed without the problem symptoms occurring, refer to
Step 8 to replace the ECU. So always confirm that the
problem symptoms are occurring, or proceed with inspec-
tion while using the symptom simulation method.

The instructions ºCheck wire harness and connectorº and
ºCheck and replace ECUº which appear in the inspection
procedure, are common and applicable to all diagnostic
trouble codes. Follow the procedure outlined below
whenever these instructions appear.
OPEN CIRCUIT:
This could be due to a disconnected wire harness, faulty con-
tact in the connector, a connector terminal pulled out, etc.
HINT:

It is rarely the case that a wire is broken in the middle of
it. Most cases occur at the connector. In particular, care-
fully check the connectors of sensors and actuators

Faulty contact could be due to rusting of the connector
terminals, to foreign materials entering terminals or a de-
formation of connector terminals. Simply disconnecting
and reconnecting the connectors once changes the
condition of the connection and may result in a return to
normal operation. Therefore, in troubleshooting, if no ab-
normality is found in the wire harness and connector
check, but the problem disappears after the check, then
the cause is considered to be in the wire harness or con-
nectors.
SHORT CIRCUIT:
This could be due to a contact between wire harness and the
body ground or to a short circuit occurred inside the switch, etc.
HINT:
When there is a short circuit between the wire harness and body
ground, check thoroughly whether the wire harness is caught
in the body or is clamped properly.

FI7187
IN0379
Sensor Side
ECU Side
IN0378
Sensor SideECU Side
IN0380
Sensor SideECU Side
IN0381
Pull Lightly
Looseness of Crimping
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-31
31 Author
: Date
:
2001 AVALON (RM808U)
2. CONNECTOR HANDLING
When inserting tester probes into a connector, insert them from
the rear of the connector. When necessary, use mini test leads.
For water resistant connectors which cannot be accessed from
behind, take good care not to deform the connector terminals.
3. CONTINUITY CHECK (OPEN CIRCUIT CHECK)
(a) Disconnect the connectors at both ECU and sensor
sides.
(b) Measure the resistance between the applicable terminals
of the connectors.
Resistance: 1 W or less
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
4. RESISTANCE CHECK (SHORT CIRCUIT CHECK)
(a) Disconnect the connectors on both ends.
(b) Measure the resistance between the applicable terminals
of the connectors and body ground. Be sure to carry out
this check on the connectors on both ends.
Resistance: 1 MW or higher
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
5. VISUAL CHECK AND CONTACT PRESSURE CHECK
(a) Disconnect the connectors at both ends.
(b) Check for rust or foreign material, etc. in the terminals of
the connectors.
(c) Check crimped portions for looseness or damage and
check that the terminals are secured in lock portion.
HINT:
The terminals should not come out when pulled lightly from the
back.

Z17004
Fig. 1
OPENECU
2 Sensor
22 21 111A B C
Z17005
Fig. 2
ECU
Sensor
21A
B C
1
1
22
B04722
Fig. 3
ECU
Sensor
21A
C1
1
2 21
2 1B1
B2
IN-32- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
32 Author
: Date
:
2001 AVALON (RM808U)
(d) Prepare a test male terminal and insert it in the female ter-
minal, then pull it out.
NOTICE:
When testing a gold-plated female terminal, always use a
gold-plated male terminal.
HINT:
When the test terminal is pulled out more easily than others,
there may be poor contact in that section.
6. CHECK OPEN CIRCUIT
For the open circuit in the wire harness in Fig. 1, perform º(a)
Continuity Checkº or º(b) Voltage Checkº to locate the section.
(a) Check the continuity.
(1) Disconnect connectors ºAº and ºCº and measure
the resistance between them.
In the case of Fig. 2:
Between terminal 1 of connector ºAº and terminal 1
of connector ºCº " No continuity (open)
Between terminal 2 of connector ºAº and terminal 2
of connector ºCº " Continuity
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ºAº and terminal 1
of connector ºCº.
(2) Disconnect connector ºBº and measure the resis-
tance between the connectors.
In the case of Fig. 3:
Between terminal 1 of connector ºAº and terminal 1
of connector ºB1º " Continuity
Between terminal 1 of connector ºB2º and terminal
1 of connector ºCº " No continuity (open)
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ºB2º and terminal
1 of connector ºCº.

Z17007
Fig. 4
Sensor
21A
C
1
1
22B5V
5V
5V
0V
Z17008
Fig. 5
2 1A C
1
1
22
BSHORT
Z17009
Fig. 6
21A C
1
1
22
BSensorECU
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-33
33 Author
: Date
:
2001 AVALON (RM808U)
(b) Check the voltage.
In a circuit in which voltage is applied (to the ECU connec-
tor terminal), an open circuit can be checked for by con-
ducting a voltage check.
As shown in Fig. 4, with each connector still con-
nected, measure the voltage between body ground
and terminal 1 of connector ºAº at the ECU 5V out-
put terminal, terminal 1 of connector ºBº, and termi-
nal 1 of connector ºCº, in that order.
If the results are:
5V: Between Terminal 1 of connector ºAº and Body Ground
5V: Between Terminal 1 of connector ºBº and Body Ground
0V: Between Terminal 1 of connector ºCº and Body Ground
Then it is found out that there is an open circuit in the wire har-
ness between terminal 1 of ºBº and terminal 1 of ºCº.
7. CHECK SHORT CIRCUIT
If the wire harness is ground shorted as in Fig. 5, locate the sec-
tion by conducting a ºcontinuity check with groundº.
Check the continuity with ground.
(1) Disconnect connectors ºAº and ºCº and measure
the resistance between terminal 1 and 2 of connec-
tor ºAº and body ground.
In the case of Fig. 6:
Between terminal 1 of connector ºAº and body
ground " Continuity (short)
Between terminal 2 of connector ºAº and body
ground " No continuity
Therefore, it is found out that there is a short circuit
between terminal 1 of connector ºAº and terminal 1
of connector ºCº.

Z17808
Fig. 7
Sensor
21A B1 C
1
1
221
2 B2
ECU
IN0383
Example
Ground
IN0384
Ground
Ground
ECU Side
W/H Side IN-34
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
34 Author
: Date
:
2001 AVALON (RM808U)
(2) Disconnect connector ºBº and measure the resis-
tance between terminal 1 of connector ºAº and body
ground, and terminal 1 of connector ºB2º and body
ground.
In the case of Fig. 7:
Between terminal 1 of connector ºAº and body
ground " No continuity
Between terminal 1 of connector ºB2º and body
ground " Continuity (short)
Therefore, it is found out that there is a short circuit
between terminal 1 of connector ºB2º and terminal
1 of connector ºCº.
8. CHECK AND REPLACE ECU
First check the ECU ground circuit. If it is faulty, repair it. If it is
normal, the ECU could be faulty, so replace the ECU with a nor-
mal functioning one and check that the symptoms appear.
(1) Measure the resistance between the ECU ground
terminal and the body ground.
Resistance: 1 W or less
(2) Disconnect the ECU connector, check the ground
terminals on the ECU side and the wire harness
side for bend and check the contact pressure.

IN0253
WRONG CORRECT
IN0252
WRONG CORRECT IN-6
- INTRODUCTIONREPAIR INSTRUCTIONS
6 Author
: Date
:
2001 AVALON (RM808U)
(k) Care must be taken when jacking up and supporting the
vehicle. Be sure to lift and support the vehicle at the prop-
er locations (See page IN-8).
Cancel the parking brake on the level place and
shift the transmission in Neutral (or N position).
When jacking up the front wheels of the vehicle at
first place stoppers behind the rear wheels.
When jacking up the rear wheels of the vehicle at
first place stoppers before the front wheels.
When either the front or rear wheels only should be
jacked up, set rigid racks and place stoppers in front
and behind the other wheels on the ground.
After the vehicle is jacked up, be sure to support it
on rigid racks . 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.

IN04Q-08
- INTRODUCTIONTERMS
IN-35
35 Author
: Date
:
2001 AVALON (RM808U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti-Lock Brake System
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir-Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
A/TAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi-Level
B/SBore-Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching Valve
Calif.California
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve

IN-38
- INTRODUCTIONTERMS
38 Author
: Date
:
2001 AVALON (RM808U) OEM
Original Equipment Manufacturing
OHCOverhead Camshaft
OHVOverhead Valve
OPTOption
O/SOversize
P & BVProportioning And Bypass Valve
PCSPower Control System
PCVPositive Crankcase Ventilation
PKBParking Brake
PPSProgressive Power Steering
PSPower Steering
PTOPower Take-Of f
R & PRack And Pinion
R/BRelay Block
RBSRecirculating Ball Type Steering
R/FReinforcement
RFSRigid Front Suspension
RRSRigid Rear Suspension
RHRight-Hand
RHDRight-Hand Drive
RLYRelay
ROMRead Only Memory
RrRear
RRRear-Engine Rear-Wheel Drive
RWDRear-Wheel Drive
SDNSedan
SENSensor
SICSStarting Injection Control System
SOCState Of Charge
SOHCSingle Overhead Camshaft
SPECSpecification
SPISingle Point Injection
SRSSupplemental Restraint System
SSMSpecial Service Materials
SSTSpecial Service Tools
STDStandard
STJCold-Start Fuel Injection
SWSwitch
SYSSystem
T/ATransaxle
TACHTachometer
TBIThrottle Body Electronic Fuel Injection
TCTurbocharger
TCCSTOYOTA Computer-Controlled System
TCVTiming Control Valve
TDCTop Dead Center