TOYOTA HIGHLANDER 2001 Service Repair Manual

A90300
8
IGF1 IGT1
E7
IGT4 R-W
GR IC3
I15
Ignition Switch
EFL-YE7
E7 1124
I5
Ignition Coil with
Igniter No. 43
2
1 4
42
2
2 3 4
4 R
R O
W-B
W-B
W-B W-B
1
N1
Noise Filter 1
Instrument
Panel J/B
Assy
AM2
IG2
1
1F7
FL Block AssyI2
Ignition Coil with
Igniter No. 1
E9 E11
A
A
EEBR
J7
J/C
BR W-B5 V
W-R
W-R
W-R
W
FL
Main
Battery 10L-Y IC1
AM2
Y
76 1C 41F 6
1G 1 IG2EB12
BRBR
1C 1ECM
IGT2 P
E79
13 W-BI3
Ignition Coil with
Igniter No. 2
IGT3 Y-B
E710
3 1 I4
Ignition Coil with
Igniter No. 3
W-B1W-R
W-R
W-R R R
R R RRW-R
S29 S284
4
Short
Connector
B
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
COMPONENT OPERATING RANGE
IGF signalIgniter outputs IGF signal when it receives IGT signal from ECM
WIRING DIAGRAM

Y
A54393
A81699
A85848
Wire Harness Side
I2
I3
I4
I5
Ignition Coil
IGF1 E7
ECM
05-178
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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 CHECK SPARK PLUG AND SPARK OF MISFIRING CYLINDER (See page 18-3)
OK: Spark occurs.
NG Go to step 4
OK
2 CHECK WIRE HARNESS (IGNITION COIL ASSY - ECM (IGF TERMINAL))
(a) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(b) Disconnect the E7 ECM connector.
(c) Measure the resistance of the wire harness side connec-
tors.
Standard:
Tester ConnectionSpecified Condition
I2-2 - E7-24 (IGF1)
I3-2 - E7-24 (IGF1)
I4-2 - E7-24 (IGF1)
I5-2 - E7-24 (IGF1)
Below 1 W
I2-2 or E7-24 (IGF1) - Body ground
I3-2 or E7-24 (IGF1) - Body ground
I4-2 or E7-24 (IGF1) - Body ground
I5-2 or E7-24 (IGF1) - Body ground
10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK

A76903
E1 (-)
E9
ECM E7
ECM IGF1 (+)
A76903
A35500A87928
E1 (-)
E9
ECM E7
ECM
IGF1 (+)
20 msec./Division2 V/
Division IGT and IGF Signal Waveform
CH2
(IGF1)
GNDGND
CH1
(IGT1 to 4)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 CHECK ECM (IGF1 VOLTAGE)
(a) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(b) Turn the ignition switch ON.
(c) Measure the voltage of the ECM connectors.
Standard:
Tester ConnectionSpecified Condition
E7-24 (IGF1) - E9-1 (E1)4.5 to 5.5 V
HINT:
Reference: Inspection using the oscilloscope.
During cranking or idling, check the waveform of the ECM con-
nectors.
Standard:
Tester ConnectionSpecified Condition
E7-24 (IGF1) - E9-1 (E1)Correct waveform is as shown
NG REPLACE ECM (See page 10-9)
OK
REPLACE IGNITION COIL ASSY

Y
A54393
A81699
A85848
Wire Harness Side
I2
I3
I4
I5
Ignition Coil
E7
ECMIGT1 (+)
IGT2 (+) IGT4 (+) IGT3 (+)
05-180
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
370 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 CHECK WIRE HARNESS (IGNITION COIL ASSY - ECM (IGT TERMINAL))
(a) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(b) Disconnect the E7 ECM connector.
(c) Measure the resistance of the wire harness side connec-
tors.
Standard:
Tester ConnectionSpecified Condition
I2-3 - E7-8 (IGT1)
I3-3 - E7-9 (IGT2)
I4-3 - E7-10 (IGT3)
I5-3 - E7-11 (IGT4)
Below 1 W
I2-3 or E7-8 (IGT1) - Body ground
I3-3 or E7-9 (IGT2) - Body ground
I4-3 or E7-10 (IGT3) - Body ground
I5-3 or E7-11 (IGT4) - Body ground
10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK

A76903
E1 (-)
E9
ECM IGT2 (+)IGT1 (+) IGT4 (+)IGT3 (+)
E7
ECM
A76903
E1 (-)
E9
ECM IGT2 (+)IGT1 (+) IGT4 (+)IGT3 (+)
E7
ECM
A76903
A35500A87928
E1 (-)
E9
ECM IGT2 (+) IGT1 (+) IGT4 (+)IGT3 (+)
E7
ECM
20 msec./Division2 V/
Division IGT and IGF Signal Waveform
CH1
(IGT1 to 4)
GNDGND
CH2
(IGF1)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
5 CHECK ECM
(a) Measure the voltage of the ECM connectors when the en-
gine is cranked.
Standard:
Tester ConnectionSpecified Condition
E7-8 (IGT1) - E9-1 (E1)
E7-9 (IGT2) - E9-1 (E1)
E7-10 (IGT3) - E9-1 (E1)
E7-1 1 (IGT4) - E9-1 (E1)
More than 0.1 V or less than 4.5 V
(b) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(c) Measure the voltage of the ECM connectors when the en-
gine is cranked.
Standard:
Tester ConnectionSpecified Condition
E7-8 (IGT1) - E9-1 (E1)
E7-9 (IGT2) - E9-1 (E1)
E7-10 (IGT3) - E9-1 (E1)
E7-1 1 (IGT4) - E9-1 (E1)
4.5 V or more
HINT:
Reference: Inspection using an oscilloscope.
During cranking or idling, check the waveform of the ECM con-
nectors.
Standard:
Tester ConnectionSpecified Condition
E7-8 (IGT1) - E9-1 (E1)
E7-9 (IGT2) - E9-1 (E1)
E7-10 (IGT3) - E9-1 (E1)
E7-1 1 (IGT4) - E9-1 (E1)
Correct waveform is as shown
NG REPLACE ECM (See page 10-9)
OK

A54393
Wire Harness Side
I2
I3
I4
I5
Ignition Coil
A90345
IG2 fuse Instrument
Panel J/B
Assy
Y
A54393
A61075
1234
5678
A85536
I2
I3
I4
I5
Ignition Coil
IG2
I15
Ignition Switch Wire Harness Side
05-182
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:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
6 CHECK IGNITION COIL ASSY (POWER SOURCE)
(a) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(b) Turn the ignition switch ON.
(c) Measure the voltage of the wire harness side connector
and body ground.
Standard:
Tester ConnectionSpecified Condition
I2-1 - Body ground
I3-1 - Body ground
I4-1 - Body ground
I5-1 - Body ground
9 to 14 V
OK REPLACE IGNITION COIL ASSY
NG
7 CHECK WIRE HARNESS (IGNITION COIL ASSY - IGNITION SWITCH)
(a) Check the IG2 fuse.
(1) Remove the IG2 fuse from the instrument panel J/B
Assy.
(2) Measure the resistance of the IG2 fuse.
Standard: Below 1 W
(b) Disconnect the I2, I3, I4 and I5 ignition coil connectors.
(c) Disconnect the I15 ignition switch connector.
(d) Measure the resistance of the wire harness side connec-
tors.
Standard:
Tester ConnectionSpecified Condition
I2-1 - I15-6 (IG2)
I3-1 - I15-6 (IG2)
I4-1 - I15-6 (IG2)
I5-1 - I15-6 (IG2)
Below 1 W
I2-1 or I15-6 (IG2) - Body ground
I3-1 or I15-6 (IG2) - Body ground
I4-1 or I15-6 (IG2) - Body ground
I5-1 or I15-6 (IG2) - Body ground
10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK

- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
REPLACE IGNITION COIL ASSY

A85838
Waveform of A/F Sensor
Before CatalystWaveform of Heated Oxygen Sensor
After Catalyst Normal Catalyst
Deteriorated Catalyst Waveform of A/F Sensor
Before CatalystWaveform of Heated Oxygen Sensor
After Catalyst 3.5 V
3.0 V
3.5 V
3.0 V1.0 V
0.5 V
1.0 V
0.5 V
10 seconds 10 seconds
0 V 0 V 05-184
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW
THRESHOLD (BANK 1)
MONITOR DESCRIPTION
The ECM uses sensors mounted before and after the three-way catalyst (TWC) to monitor its efficiency. The
first sensor, an Air Fuel ratio (A/F) sensor, sends pre-catalyst A/F ratio information to the ECM. The second
sensor, a heated oxygen sensor (O2S), sends post-catalyst information to the ECM. The ECM compares
these two signals to judge the efficiency of the catalyst and the catalyst's ability to store oxygen. During nor-
mal operation, the TWC stores and releases oxygen as needed. The capacity to store oxygen results in a
low variation in the post-TWC exhaust stream as shown below.
If the catalyst is functioning normally, the waveform of the heated oxygen sensor slowly switches between
RICH and LEAN. If the catalyst is deteriorated, the waveform will alternate frequently between RICH and
LEAN. As the catalyst efficiency degrades, its ability to store oxygen is reduced and the catalyst output be-
comes more variable. When running the monitor, the ECM compares sensor 1 signals (A/F sensor) over a
specific amount of time to determine catalyst efficiency. The ECM begins by calculating the signal length for
both sensors (for the rear oxygen sensor, the ECM uses the output voltage signal length). If the oxygen sen-
sor output voltage signal length is greater than the threshold (threshold is calculated based on the A/F sensor
signal length), the ECM concludes that the catalyst is malfunctioning. The ECM will turn on the MIL and a
DTC will be set.
05EW2-05

A82718
Signal Length
Time Sensor
Output
Voltage Heated Oxygen Sensor Signal Length
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-185
375 Author
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2005 HIGHLANDER REPAIR MANUAL (RM1144U)DTC No.
DTC Detection ConditionTrouble Area
P0420
After engine and catalyst are warmed up, and while vehicle is
driven within set vehicle and engine speed, waveform of
heated oxygen sensor (bank 1 sensor 2) alternates frequently
between RICH and LEAN (2 trip detection logic)
Gas leakage in exhaust system

A/F sensor (bank 1 sensor 1)

Heated oxygen sensor (bank 1 sensor 2)

Three-way catalytic converter (Exhaust manifold)
HINT:

Sensor 1 is the sensor closest to the engine assembly.

Sensor 2 is the sensor farthest away from the engine assembly.
MONITOR STRATEGY
Related DTCsP0420: Catalyst deterioration
Required sensors / components (Main)Catalyst
Required sensors / components (Related)A/F sensor, Heated oxygen sensor (HO2S), IAT sensor, MAF meter, CKP sensor,
ECT sensor
Frequency of operationOnce per driving cycle
Duration150 sec. (30 sec. x 5)
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever this DTC is not presentSee page 05-16
Accumulated time that the following conditions are met:30 sec.
Battery voltage11 V or more
IAT-10C (14F) or more
Idle statusOFF
MAF8 to 35 g/sec.
Engine RPMLess than 4,500 rpm
ECT75C (167F) or more
Rich experience after fuel cutYe s
Fuel system statusClosed Loop
A/F sensorActivated
Rear HO2SActivated
Estimated catalyst temperatureBoth of the following conditions 1 and 2 are met:
1. Upstream catalyst temperature500 to 900C (932 to 1,652F)
2. Downstream catalyst temperature350 to 900C (662 to 1,652F)

Engine Speed
3,000 rpm
Idling
IG SW OFF
Warmed upTime (a) 2,000 rpm
(b)(c) (d)
A90911
3 minutes or so
2 seconds
2 seconds
Check 05-186
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
376 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TYPICAL MALFUNCTION THRESHOLDS
Rear HO2S locus length13 V or more (Varies with A/F sensor locus length)
Frequency of the monitor4 times
MONITOR RESULT
Refer to page 05-24 for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (see page 05-26).

TID (Test Identification Data) is assigned to each emissions-related component.

TLT (Test Limit Type):
If TLT is 0, the component is malfunctioning when the test value is higher than the test limit.
If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.

CID (Component Identification Data) is assigned to each test value.

Unit Conversion is used to calculate the test value indicated on generic OBD ll scan tools.
TID $01: Catalyst - Sensor 1 A/F sensor, Sensor 2 HO2S
TLTCIDUnit ConversionDescription of Test DataDescription of Test Limit
0$01Multiply by 0.0078
(no dimension)Catalyst deterioration level:
Determined by waveforms of A/F sensor
and HO2S
Malfunction criteria for catalyst deterioration
CONDITIONING A/F SENSOR AND HEATED OXYGEN SENSOR FOR TESTING
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Start the engine and warm it up with all the accessories switched OFF until the Engine Coolant Temper-
ature (ECT) is stable.
(c) Run the engine at 2,500 to 3,000 rpm for about 3 minutes.
(d) When alternating the engine between 3,000 rpm and 2,000 rpm for 2 seconds respectively, check the
waveform of the oxygen sensor (bank 1 sensor 2).
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.