engine TOYOTA HIGHLANDER 2001 Service Repair Manual
[x] Cancel search | Manufacturer: TOYOTA, Model Year: 2001, Model line: HIGHLANDER, Model: TOYOTA HIGHLANDER 2001Pages: 2572, PDF Size: 34.8 MB
Page 1638 of 2572
05-70
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
260 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
WIRING DIAGRAM
Refer to DTCs P0335 and P0339 on page 05-166.
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 VALVE TIMING (See page 14-68)
(a) Check for loose or jumped tooth of timing chain.
OK: The matchmarks of the crankshaft pulley and camshaft pulley are alined.
NG ADJUST VALVE TIMING (See page 14-68)
OK
REPLACE ECM (See page 10-9)
Page 1639 of 2572
A90346
Reference
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
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-71
261 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0031 OXYGEN (A/F) SENSOR HEATER CONTROL
CIRCUIT LOW (BANK 1 SENSOR 1)
DTC P0032 OXYGEN SENSOR HEATER CONTROL
CIRCUIT HIGH (BANK 1 SENSOR 1)
HINT:
Although the title (DTC description) says ºoxygen sensorº, this DTC is related to the ºA/F sensorº.
CIRCUIT DESCRIPTION
Refer to DTC P2195 on page 05-269.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The A/F sen-
sor heater circuit uses a relay on the +B side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0031Heater current of 0.8 A or less when heater operates
(1 trip detection logic)
Open in heater circuit of A/F sensor
A/F sensor heater
EFI relay
ECM
P0032Heater current exceeds 10 A when heater operates
(1 trip detection logic)
Short in heater circuit of A/F sensor
A/F sensor heater
EFI relay
ECM
HINT:
Sensor 1 is the sensor closest to the engine assembly.
05ET1-06
Page 1640 of 2572
05-72
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
262 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR DESCRIPTION
The ECM uses A/F sensor information to keep the air/fuel ratio close to the stoichiometric ratio. This maxi-
mizes the catalytic converter's ability to purify exhaust gas. The sensor detects oxygen levels in the exhaust
gas and sends this signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element
is exposed to exhaust gas. The sensor element is made of platinum coated zirconia and includes an inte-
grated heating element. The zirconia element generates small voltage when there is a large difference in
the oxygen concentrations of the exhaust and the outside air. The platinum coating amplifies the voltage
generation. When heated, the sensor becomes very efficient. If the temperature of the exhaust is low, the
sensor will not generate useful voltage signals without supplemental heating. The ECM regulates the sup-
plemental heating using a duty-cycle approach to regulate the average current in the heater element. If the
heater current is out of the normal range, the sensor's output signals will be inaccurate and the ECM cannot
regulate the A/F ratio properly.
When the heater current is out of the normal operating range, the ECM interprets this as a malfunction and
sets a DTC.
MONITOR STRATEGY
Related DTCsP0031: A/F sensor heater range check (Low current)
P0032: A/F sensor heater range check (High current)
Required sensors / components (Main)A/F sensor heater
Required sensors / components (Related)-
Frequency of operationContinuous
Duration10 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
P0031:
Battery voltageLess than 10.5 V
A/F sensor heater duty ratio50 % or more
Time after engine start10 sec. or more
P0032:
Time after engine start10 sec. or more
TYPICAL MALFUNCTION THRESHOLDS
P0031:
A/F sensor heater currentLess than 0.8 A
P0032:
A/F sensor heater currentMore than 10 A
COMPONENT OPERATING RANGE
A/F sensor heater current1.8 to 3.4 A at 20°C (68°F)
Page 1641 of 2572
A52607
AF-AF+
A6
A/F sensor
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-73
263 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
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 $07: A/F sensor heater
TLTCIDUnit ConversionDescription of Test DataDescription of Test Limit
1$01Multiply by 0.00017
(A)Maximum heater currentMalfunction criterion for A/F sensor heater
WIRING DIAGRAM
Refer to DTC P2195 on page 05-269.
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 INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
(a) Disconnect the A6 A/F sensor connector.
(b) Measure the resistance between the terminals of the A/F
sensor.
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
Page 1642 of 2572
B60778
5
12 312
5
3
A76903
HA1A (+)E1 (-)
E8
ECME9
ECM
05-74
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
264 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 INSPECT RELAY (EFI)
(a) Remove the EFI relay from the engine room J/B.
(b) Measure the resistance of the EFI relay.
Standard:
Tester ConnectionSpecified Condition
3 - 510 kW or higher
3 - 5Below 1 W
(when battery voltage is applied to terminals 1 and 2)
NG REPLACE RELAY
OK
3 CHECK ECM (HA1A VOLTAGE)
(a) Turn the ignition switch ON.
(b) Measure the voltage of the ECM connectors.
Standard:
Tester ConnectionSpecified Condition
E8-5 (HA1A) - E9-1 (E1)9 to 14 V
OK REPLACE ECM (See page 10-9)
NG
Page 1643 of 2572
12
34
A81695
A76787A85433
Wire Harness Side
A6
A/F Sensor
HT
+B
HA1AE8
ECM
12
34
A90291
A76787A90920
Wire Harness Side
A6
A/F Sensor
HT
+B
EFI Relay
Engine Room J/B
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-75
265 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 CHECK WIRE HARNESS (ECM - A/F SENSOR, A/F SENSOR - EFI RELAY)
(a) Check the wire harness between the ECM and A/F sen-
sor.
(1) Disconnect the E8 ECM connector.
(2) Disconnect the A6 A/F sensor connector.
(3) Measure the resistance of the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
A6-1 (HT) - E8-5 (HA1A)Below 1 W
A6-1 (HT) or E8-5 (HA1A) - Body ground10 kW or higher
(b) Check the wire harness between the A/F sensor and EFI
relay.
(1) Disconnect the A6 A/F sensor connector.
(2) Remove the EFI relay from the engine room J/B.
(3) Measure the resistance of the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
A6-2 (+B) - J/B EFI relay terminal 3Below 1 W
A6-2 (+B) or J/B EFI relay terminal 3 -Body ground10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
REPLACE ECM (See page 10-9)
Page 1644 of 2572
A90346
Reference
Heater
Sensor
Duty
Control ECM
From
Battery
EFI NO. 1
FuseEFI Relay
+B HT
EFI NO. 2
Fuse
MREL OX1B HT1B Heated Oxygen Sensor
OB1- OX E1 05-76
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
266 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC P0037 OXYGEN SENSOR HEATER CONTROL
CIRCUIT LOW (BANK 1 SENSOR 2)
DTC P0038 OXYGEN SENSOR HEATER CONTROL
CIRCUIT HIGH (BANK 1 SENSOR 2)
CIRCUIT DESCRIPTION
Refer to DTC P0136 on page 05-1 18.
HINT:
The ECM provides a pulse width a modulated control circuit to adjust current through the heater. The oxygen
sensor heater circuit uses a relay on the +B side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0037
Heater current of less than 0.3 A when the heater operates
with +B greater than 10.5 V
(1 trip detection logic)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
EFI relay
ECM
P0038Heater current exceeds 2 A when heater operates
(1 trip detection logic)Same as DTC No. P0037
HINT:
Sensor 2 is the sensor farthest away from the engine assembly.
MONITOR DESCRIPTION
The sensing portion of the heated oxygen sensor has a zirconia element that is used to detect oxygen con-
centration in the exhaust. If the zirconia element is at the proper temperature and the difference of the oxy-
gen concentration between the inside and outside surface of the sensor is large, the zirconia element will
generate voltage signals. In order to increase the oxygen concentration detecting capacity in the zirconia
element, the ECM supplements the heat from the exhaust with heat from a heating element inside the sen-
sor. When current in the sensor is out of the standard operating range, the ECM interprets this as a fault in
the heated oxygen sensor and sets a DTC.
Example:
The ECM will set a high current DTC if the current in the sensor is more than 2 A when the heater is OFF.
Similarly, the ECM will set a low current DTC if the current is less than 0.25 A when the heater is ON.
05ETE-05
Page 1645 of 2572
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-77
267 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
MONITOR STRATEGY
Related DTCsP0037: HO2S heater range check (Low current)
P0038: HO2S heater range check (High current)
Required sensors / components (Main)Heated oxygen sensor (HO2S) heater
Required sensors / components (Related)Vehicle speed sensor (VSS)
Frequency of operationContinuous
Duration0.3 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
All:
The monitor will run whenever these DTCs are not presentSee page 05-16
P0037:
Battery voltage10.5 V or more
EngineRunning
StarterOFF
Intrusive heatingNot operated
P0038 (Case 1):
Battery voltage10.5 V or more
EngineRunning
StarterOFF
Intrusive heatingNot operated
P0038 (Case 2):
Battery voltage10.5 V or more
All heater is turned OFF and intrusive heating is operated
when the following conditions are metCondition 1 and 2
1. HeaterON
2. Heater current2 A or more
TYPICAL MALFUNCTION THRESHOLDS
P0037:
HO2S heater current intrusive heatingLess than 0.3 A
P0038 (Case 1):
HO2S heater current2 A or more
P0038 (Case 2):
HO2S heater current intrusive heatingMore than 2 A
COMPONENT OPERATING RANGE
HO2S heater current0.4 to 1 A (when engine is idle, warmed-up and battery voltage is 11 to 14 V)
Page 1646 of 2572
A80018
H10
Heated Oxygen Sensor
+B HT
E1 OX
05-78
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
268 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
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 $04: HO2S heater
TLTCIDUnit ConversionDescription of Test DataDescription of Test Limit
1$02Multiply by 0.000076
(A)Maximum HO2S heater current
(Bank 1 Sensor 2)Malfunction threshold for HO2S heater
WIRING DIAGRAM
Refer to DTC P0136 on page 05-1 18.
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 INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
(a) Disconnect the H10 heated oxygen sensor connector.
(b) Measure the resistance of the heated oxygen sensor ter-
minals.
Standard:
Tester ConnectionConditionSpecified Condition
H10-2 (HT) - H10-1 (+B)20C (68F)11 to 16 W
H10-2 (HT) - H10-1 (+B)800C (1,472F)23 to 32 W
NG REPLACE HEATED OXYGEN SENSOR
OK
Page 1647 of 2572
B60778
5
1
2 312
5
3
A76903
E9
ECME1 (-)
E8
ECM HT1B (+)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
05-79
269 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 INSPECT RELAY (EFI)
(a) Remove the EFI relay from the engine room J/B.
(b) Measure the resistance of the EFI relay.
Standard:
Tester ConnectionSpecified Condition
3 - 510 kW or higher
3 - 5Below 1 W
(when battery voltage is applied to terminals 1 and 2)
NG REPLACE RELAY
OK
3 INSPECT ECM (HT1B VOLTAGE)
(a) Turn the ignition switch ON.
(b) Measure the voltage of the ECM connectors.
Standard:
Tester ConnectionSpecified Condition
E8-21 (HT1B) - E9-1 (E1)9 to 14 V
OK REPLACE ECM (See page 10-9)
NG