TOYOTA HIGHLANDER 2001 Service Repair Manual

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

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

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)

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

- 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)

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

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

A81695
A80019A91528
Wire Harness Side
E8
ECM
H10
Heated Oxygen Sensor
HT +B
OX E1 HT1B
A80019
A90291A91529
Wire Harness Side
H10
Heated Oxygen Sensor
HT
+B
OX
E1
EFI RelayEngine Room J/B
05-80
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)
270 Author
: Date
:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 CHECK WIRE HARNESS (ECM - HEATED OXYGEN SENSOR, HEATED OXYGEN
SENSOR - EFI RELAY)
(a) Check the wire harness between the ECM and heated ox-
ygen sensor.
(1) Disconnect the E8 ECM connector.
(2) Disconnect the H10 heated oxygen sensor connec-
tor.
(3) Measure the resistance of the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
H10-2 (HT) - E8-21 (HT1B)Below 1 W
H10-2 (HT) or E8-21 (HT1B) - Body ground10 kW or higher
(b) Check the wire harness between the heated oxygen sen-
sor and EFI relay.
(1) Disconnect the H10 heated oxygen sensor connec-
tor.
(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
H10-1 (+B) - J/B EFI relay terminal 3Below 1 W
H10-1 (+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)

05-190
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)(From August, 2004)
380 Author
: Date
:
DTC P043E EVAPORATIVE EMISSION SYSTEM
REFERENCE ORIFICE CLOG UP
DTC P043F EVAPORATIVE EMISSION SYSTEM
REFERENCE ORIFICE HIGH FLOW
CIRCUIT DESCRIPTION
Refer to EVAP Inspection Procedure (see page 05-317).
DTCsMonitoring ItemDetection ConditionTrouble AreaDetection
TimingDetection
Period
P043E0.02 inch orifice clogged
(built-in pump module)
To determine leak criterion (Reference
pressure), vacuum pump creates negative
pressure in canister pump module through
0.02 inch orifice and pressure is measured.
If one of following conditions is met, ECM
setspumpmodule related DTCs: P043E

Pump module

Connector / wire harness
Ignition2 trips
P043F0.02 inch orifice high-flow
(built-in pump module)
sets pump module related DTCs: P043E,
P043F, P2401, P2402 and P2419:

Reference pressure is -1 kPa or higher

Reference pressure is -4.85 kPa or lower

Reference pressure is not saturated within
60 secondsConnector / wire harness
(Pump module - ECM)

ECM
Ignition
OFF2 trips
WIRING DIAGRAM
Refer to EVAP Inspection Procedure (see page 05-317).
INSPECTION PROCEDURE
Refer to EVAP Inspection Procedure (see page 05-317).
05PGO-01

A96746
Fuel Tank Canister
Vacuum Pump: OFF Pressure Sensor 0.02 Inch Orifice
Pump Module
Operation A: Atmospheric Pressure Measurement
Vent Valve: OFF (vent)
Operation D: Purge VSV monitor Operation B, E: 0.02 Inch Leak Pressure Measurement
Negative
Pressure Atmospheric
Pressure
Operation C: EVAP System Pressure Measurement
Air Filter
Purge VSV: OFFOFF (vent)
ON
OFF
OFF
ON
ON (closed)ON
ON
ON (closed)
- DIAGNOSTICSSFI SYSTEM (2AZ-FE)(From August, 2004)
05-191
381 Author
: Date
:
MONITOR DESCRIPTION
5 hours* after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacu-
um) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions
based on the EVAP pressure.
HINT:
*: If the engine coolant temperature is not below 35C (95F) after 5 hours after the ignition switch is turned
off, the monitor check starts 2 hours later. If it is still not below 35C (95F) 7 hours after the ignition switch
is turned off, the monitor check starts 2.5 hours later.
SequenceOperationsDescriptionsDuration
-ECM activationActivated by soak timer, 5 hours (7 or 9.5 hours) after ignition switch turned to OFF.-
AAtmospheric pressure
measurement
Vent valve turned OFF (vent) and EVAP system pressure measured by ECM in order to
register atmospheric pressure.
If EVAP pressure is not between 70 kPa and 110 kPa (525 mmHg and 825 mmHg), ECM
cancels EVAP system monitor.
10 seconds
B
First 0.02 inch leak
pressure measure-
mentIn order to determine 0.02 inch leak pressure standard, vacuum pump creates negative pres-
sure (vacuum) through 0.02 inch orifice and then ECM checks if vacuum pump and vent
valve operate normally.
60 seconds
CEVAP system pres-
sure measurement
Vent valve turned ON (closed) to shut EVAP system.
Negative pressure (vacuum) created in EVAP system, and EVAP system pressure then
measured.
Write down the measured value as it will be used in the leak check.
If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.
15 minutes*
DPurge VSV monitorPurge VSV opened and then EVAP system pressure measured by ECM.
Large increase indicates normal.10 seconds
E
Second 0.02 inch leak
pressure measure-
mentLeak check is performed after second 0.02 inch leak pressure standard is measured.
If stabilized system pressure higher than second 0.02 inch leak pressure standard, ECM
determines that EVAP system leaking.
60 seconds
FFinal checkAtmospheric pressure measured and then monitoring result recorded by ECM.-
* If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.