o2 sensor TOYOTA HIGHLANDER 2001 Service Repair Manual

A52607
AF-AF+
A6
A/F sensor
05-140
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
330 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
HINT:

Whenever the output voltage of the A/F sensor remains at approximately 3.3 V (0.660 V)* (see ºMal-
function Conditionº graphic) under any condition as well as the above conditions, the A/F sensor may
have an open circuit (this will happen also when the A/F sensor heater has an open circuit).

Whenever the output voltage of the A/F sensor remains at a certain value of approximately 3.8 V (0.76
V)* or more, or 2.8 V (0.56 V)* or less (see ºMalfunction Conditionº graphic) under any condition as
well as the above conditions, the A/F sensor may have a short circuit.

The ECM will stop fuel injection (fuel cut) during engine deceleration. This will cause a LEAN condition
and should result in a momentary increase in A/F sensor voltage output.

The ECM must establish a closed throttle position learned value to perform fuel cut. If the battery termi-
nal has been disconnected, the vehicle must be driven over 10 mph (16 km/h) to allow the ECM to learn
the closed throttle position.

When the vehicle is driven:
You may notice that the output voltage of the A/F sensor is below 2.8 V (0.76 V)* during fuel enrich-
ment. For example, when the vehicle tries to overtake another vehicle on a highway, the vehicle speed
is suddenly increased with the accelerator pedal fully depressed. The A/F sensor is functioning normal-
ly.

The A/F sensor is a current output element, and therefore the current is converted into voltage inside
the ECM. If measuring voltage at connectors of A/F sensor or ECM, you will observe a constant volt-
age.
*: Voltage when using the OBD II scan tool.
OK Go to step 17
NG
10 INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
(a) Disconnect the A6 A/F sensor connector.
(b) Measure the resistance of the A/F sensor terminals.
Standard:
Tester ConnectionConditionSpecified Condition
1 (HT) - 2 (+B)20C (68F)1.8 to 3.4 W
1 (HT) - 4 (AF-)-10 kW or higher
NG REPLACE AIR FUEL RATIO SENSOR
OK

A90346
A/F Sensor
Heater
Sensor
A1A+ HA1A
Duty
Control ECM
From
Battery
EFI NO. 1
Fuse
A1A-
MREL EFI Relay
+B
AF-
AF+ HT
EFI NO. 2
Fuse Reference (Bank 1 Sensor 1 System Drawing)
12
34
Y
A76787
A81695A85512
Wire Harness Side
A6
A/F Sensor
+B
AF- HT
AF+
E8
ECM
A1A+
A1A-
HA1A
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
12 CHECK WIRE HARNESS (A/F SENSOR - ECM)
(a) Disconnect the A6 A/F sensor connector.
(b) Disconnect the E8 ECM connector.
(c) Measure the resistance of the wire harness side connec-
tors.
Standard:
Tester ConnectionSpecified Condition
A6-3 (AF+) - E8-23 (A1A+)
A6-4 (AF-) - E8-31 (A1A-)
A6-1 (HT) - E8-5 (HA1A)
Below 1 W
A6-3 (AF+) or E8-23 (A1A+) - Body ground
A6-4 (AF-) or E8-31 (A1A-) - Body ground
A6-1 (HT) or E8-5 (HA1A) - Body ground
10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
13 REPLACE AIR FUEL RATIO SENSOR
GO

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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
16 CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO CHECK FOR INTERMITTENT PROBLEMS
(See page 05-9)
YES
DTC IS CAUSED BY RUNNING OUT OF FUEL (DTCS P0171, P0172)
17 PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs prior to performing the confirmation driving pattern (refer to step 14).
GO
18 READ OUTPUT DTC (DTC P0171, P0172 ARE OUTPUT AGAIN)
(a) Read the DTC using the hand-held tester or the OBD II scan tool.
Result:
Display (DTC Output)Proceed to
DTC P0171, P0172 are output againA
DTC P0171, P0172 are not output againB
B Go to step 22
A
19 REPLACE AIR FUEL RATIO SENSOR
GO
20 PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs prior to performing the confirmation driving pattern (refer to step 14).
GO

05-146
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0300 RANDOM/MULTIPLE CYLINDER MISFIRE
DETECTED
DTC P0301 CYLINDER 1 MISFIRE DETECTED
DTC P0302 CYLINDER 2 MISFIRE DETECTED
DTC P0303 CYLINDER 3 MISFIRE DETECTED
DTC P0304 CYLINDER 4 MISFIRE DETECTED
CIRCUIT DESCRIPTION
When a misfire occurs in the engine, hydrocarbons (HC) are output in high concentrations. If this HC con-
centration is high enough, there could be an increase in exhaust emission levels. High concentrations of HC
can also cause the temperature of the catalyst to increase, possibly damaging the catalyst. To prevent in-
creases in emissions and limit the possibility of thermal damage, the ECM monitors the misfire rate. When
the temperature of the catalyst reaches a point of thermal degradation, the ECM will blink the MIL. For moni-
toring misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The
camshaft position sensor is used to identify misfiring cylinders and the crankshaft position sensor is used
to measure variations in the crankshaft rotation speed. A misfire is counted when crankshaft rotation speed
variations exceed threshold values.
If the misfiring rate exceeds the threshold value and could cause emission deterioration, the ECM illuminates
the MIL.
05ETT-05

A90871
Crankshaft Position Sensor
(36-2 teeth or 12 teeth)ECM
Camshaft Position Sensor
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)DTC No.
DTC Detection ConditionTrouble Area
P0300Misfiring of random cylinders is detected

Open or short in engine wire

Connector connection

Vacuum hose connection

Ignition system

Injector

Fuel pressure

MAF meter

ECT sensor

Compression pressure

Valve clearance

Valve timing

PCV hose connection

PCV hose

ECM
P0301
P0302
Misfiring of each cylinder is detected
Same as DTC No P0300P0302
P0303
P0304Misfiring of each cylinder is detected
Same as DTC No. P0300
HINT:
When several codes for a misfiring cylinder are recorded repeatedly but no random misfire code is recorded,
the misfires have been detected and recorded at different times.
MONITOR DESCRIPTION
The ECM illuminates the MIL (2 trip detection logic) if:

The misfiring rate exceeds a threshold value and could cause emission deterioration.

During the first 1,000 engine revolutions after the engine starts, an excessive misfire rate (approxi-
mately 20 to 50 misfires per 1,000 engine revolutions) occurs 1 time.

After the first 1,000 engine revolutions after the engine starts, an excessive misfire rate (approximately
20 to 50 misfires per 1,000 engine revolutions) occurs 4 times.
The ECM blinks the MIL (MIL blinks immediately) if:

Within 200 engine revolutions at a high rpm, the threshold for ºpercentage of misfire causing catalyst
damageº is reached 1 time.

Within 200 engine revolutions at a normal rpm, the threshold for ºpercentage of misfire causing catalyst
damageº is reached 3 times. (for the 2nd trip, reaching the threshold once will cause the MIL to flash)

05-148
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCs
P0300: Multiple cylinder misfire
P0301: cylinder 1 misfire
P0302: cylinder 2 misfire
P0303: cylinder 3 misfire
P0304: cylinder 4 misfire
Required sensors / components (Main)Injector, ignition coil, spark plug
Required sensors / components (Related)CKP, CMP, ECT, IAT and MAF meter
Frequency of operationContinuous
Duration1,000 revolutions: Emission-related-misfire
200 revolutions: Catalyst-damaged-misfire
MIL operation2 driving cycles (MIL flashes immediately when Catalyst-damaged-misfire occurs)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
Battery voltage8 V or more
Throttle position learningCompleted
VVT systemNot operated by scan tool
Engine RPM400 to 6,200 rpm
All of the following conditions are met:Condition 1 and 2
1. Engine Coolant Temperature (ECT)-10C (14F) or more
2. Either of the following conditions is met:Condition (a) or (b)
(a) ECT at engine startMore than -7C (19.4F)
(b) ECTMore than 20C (68F)
Fuel-cutOFF
Monitor Period of Emission-related-misfire:
First 1,000 revolutions after engine start, or check modeCrankshaft 1,000 revolutions
Except aboveCrankshaft 1,000 revolutions y 4
Monitor Period of Catalyst-damage-misfire (MIL blinks):
All of the following conditions 1, 2 and 3 met:Crankshaft 200 revolutions
1. Driving cycles1st
2. Check ModeOFF
3. Engine RPMLess than 3,800 rpm
Except aboveCrankshaft 200 revolutions x 3
TYPICAL MALFUNCTION THRESHOLDS
Monitor Period of Emission-related-misfire:
Misfire rate4.0 % or more
Monitor Period of Catalyst-damage-misfire (MIL blinks):
Number of misfire per 200 revolutions129 or more (varies with intake air amount and engine RPM)

S01196S01699
30
20
10
5
3
02040 0.11
0.3
0.2 0.52
60 80 100 -20
(-4) (104) (140) (176)(32) (68) (212)
A81700
Ohmmeter
Acceptable
Temperature C (F)
Resistance kW
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
17 READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (INTAKE AIR
TEMPERATURE AND MASS AIR FLOW RATE)
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Turn the ignition switch ON.
(c) Check the intake air temperature.
(1) On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / EN-
HANCED OBD II / DATA LIST / ALL / INTAKE AIR. Read the values.
Temperature: Equivalent to ambient temperature
(d) Check the air flow rate.
(1) On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / EN-
HANCED OBD II / DATA LIST / ALL / MAF. Read the values.
Standard:
ConditionAir Flow Rate (gm/s)
Ignition switch ON (do not start engine)0
Idling0.5 to 5
Running without load (2,500 rpm)3 to 10
Idling to quickly acceleratingAir flow rate fluctuates
NG REPLACE MASS AIR FLOW METER
OK
18 INSPECT ENGINE COOLANT TEMPERATURE SENSOR (RESISTANCE)
(a) Remove the ECT sensor.
(b) Measure the resistance between the terminals.
Standard:
Tester ConnectionConditionSpecified Condition
1 - 220C (68F)2.32 to 2.59 kW
1 - 280C (176F)0.310 to 0.326 kW
NOTICE:
If checking the ECT sensor in water, be careful not to allow
water to contact the terminals. After the check, dry the sen-
sor.
HINT:
Alternate procedure: Connect an ohmmeter to the installed
ECT sensor and read the resistance. Use an infrared thermom-
eter to measure the engine temperature in the immediate vicin-
ity of the sensor. Compare these values to the resistance/tem-
perature graph. Change the engine temperature (warm up or
allow to cool down) and repeat the test.
NG REPLACE ENGINE COOLANT TEMPERATURE
SENSOR
OK

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0325 KNOCK SENSOR 1 CIRCUIT (BANK 1 OR
SINGLE SENSOR)
DTC P0327 KNOCK SENSOR 1 CIRCUIT LOW INPUT
(BANK 1 OR SINGLE SENSOR)
DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH INPUT
(BANK 1 OR SINGLE SENSOR)
CIRCUIT DESCRIPTION
A flat type knock sensor (non-resonant type) can detect vibrations in a wide band of frequency (about 6 kHz
to 15 kHz) and has the following features:

Knock sensors is fitted on the cylinder block to detect the engine knocking.

The sensor contains a piezoelectric element which generates a voltage when the cylinder block vi-
brates. If engine knocking occurs, the ignition timing is retarded to suppress it.
DTC No.DTC Detection ConditionTrouble Area
P0325Open or short in knock sensor circuit
(1 trip detection logic)
Open or short in knock sensor circuit

Knock sensor

ECM
P0327Output voltage of the knock sensor is 0.5 V or less
(1 trip detection logic)
Short in knock sensor circuit

Knock sensor

ECM
P0328Output voltage of the knock sensor is 4.5 V or more
(1 trip detection logic)
Open in knock sensor circuit

Knock sensor

ECM
HINT:
If the ECM detects the DTC P0325, it enters the fail-safe mode in which the corrective retarded angle value
is set to the maximum value.
MONITOR DESCRIPTION
The knock sensor, located on the cylinder block, detects spark knock. When a spark knock occurs, the sen-
sor vibrates in a specific frequency range. When the ECM detects the voltage in this frequency range, it re-
tards the ignition timing to suppress the spark knock.
The ECM also senses background engine noise with the knock sensor and uses this noise to check for faults
in the sensor. If the knock sensor signal level is too low for more than 10 seconds, and if the knock sensor
output voltage is out of normal range, the ECM interprets this as a fault in the knock sensor and sets a DTC.
05ESX-04

A90298
K1
Knock Sensor
1Shielded
J7
J/C
A A1
E8ECM
KNK1
EE 2
E8
E9 28
1
BRFKNK1
E1 BR
BR B
W
A5 V 05-162
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
352 Author
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCs
P0325: Knock sensor range check (chattering)
P0327: Knock sensor range check (low voltage)
P0328: Knock sensor range check (high voltage)
Required sensors / components (Main)Knock sensor
Required sensors / components (Related)MAF meter, CKP sensor, ECT sensor
Frequency of operationContinuous
Duration1 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these DTCs are not presentSee page 05-16
Battery voltage10.5 V or more
Time after engine start5 sec. or more
TYPICAL MALFUNCTION THRESHOLDS
Knock Sensor Range Check (Chattering) P0325:
Knock sensor voltageLess than 0.5 V, or more than 4.5 V
Knock Sensor Range Check (Low voltage) P0327:
Knock sensor voltageLess than 0.5 V
Knock Sensor Range Check (High voltage) P0328:
Knock sensor voltageMore than 4.5 V
WIRING DIAGRAM

A85381
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help deter-
mine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean
or rich, and other data from the time the malfunction occurred.
1 READ OUTPUT DTC
(a) Clear the DTC (see page 05-38).
(b) Warm up the engine.
(c) Run the engine at 3,000 rpm for 10 seconds or more.
(d) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(e) Turn ON the ignition switch. Push the hand-held tester or the OBD II scan tool main switch ON.
(f) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(g) Read the DTC.
Result:
Display (DTC output)Proceed to
Only P0325 is output againA
P0325, P0327 and/or P0328 are output againB
P0325, P0327 and/or P0328 are not output againC
B Go to step 3
C CHECK FOR INTERMITTENT PROBLEMS
(See page 05-9)
A
2 INSPECT KNOCK SENSOR
(a) Check the knock sensor installation.
OK: Torque is 20 NVm (204 kgfVcm, 15 ftVlbf)
NG TIGHTEN SENSOR
OK
REPLACE KNOCK SENSOR