TOYOTA LAND CRUISER 1998 Factory Repair Manual

DI-132
- DIAGNOSTICSENGINE
325 Author
: Date
:
2004 LAND CRUISER (RM1071U)
The following A/F CONTROL procedure enables the technician to check and graph the voltage output of
the heated oxygen sensors (sensor 1 and 2).
For displaying the graph indication, enter ºACTIVE TEST / A/F CONTROL / USER DATAº then select ºO2S
B1S1 and O2S B1S2º by pressing ºYESº button and push ºENTERº button before pressing ºF4º button.
HINT:

If different DTCs related to different systems terminal E2 as the ground terminal are output simulta-
neously, terminal E2 may be open.

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, it is useful for determin-
ing whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio
was lean or rich, etc. at the time of the malfunction.

A high heated oxygen sensor (sensor 1) voltage (0.5 V or more) could be caused by a rich air fuel mix-
ture. Check for conditions that would cause the engine to run rich.

A low heated oxygen sensor (sensor 1) voltage (0.4 V or less) could be caused by a lean air fuel mix-
ture. Check for conditions that would cause the engine to run lean.
1 Are there any other codes (besides DTCs P0134 and P0154) being output?
PREPARATION:
(a) Connect the hand-held tester or the OBD II scan tool to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester or OBD II scan tool main switch ON.
(c) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand-held tester or the OBD II scan tool.
RESULT:
Display (DTC Output)Proceed to
ºP0134 and/or P0154ºA
ºP0134 or P0154º and other DTCsB
HINT:
If any other codes besides P0134 and/or P0154 are output, perform the troubleshooting for those codes first.
B Go to relevant DTC chart (See page DI-36).
A

- DIAGNOSTICSENGINE
DI-133
326 Author
: Date
:
2004 LAND CRUISER (RM1071U)
2 Connect OBD II scan tool or hand-held tester, and read value for voltage output
of heated oxygen sensor (bank 1, 2 sensor 1).
PREPARATION:
(a) Connect the OBD II scan tool or the hand-held tester to the DLC3.
(b) Warm up the engine to the normal operating temperature.
(c) When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / O2S B1 S1 or B2 S1.
CHECK:
Read the voltage output of the heated oxygen sensors when the engine speed is suddenly increased.
HINT:
Quickly accelerate the engine to 4,000 rpm 3 times by using the accelerator pedal.
OK:
Heated oxygen sensor output a RICH signal (0.45 V or more) at least once.
OK Go to step 12.
NG
3 Check connection of PCV piping.
NG Repair or replace PCV piping.
OK

A20870
E1 +B
OX
+BHT
OX E1HT H5
H7
H6
H8
Components Side:
Bank1 Sensor1, Bank2 Sensor1
Bank1 Sensor2, Bank2 Sensor2
A21543
1
23
4 EFI or ECD Relay
DI-134
- DIAGNOSTICSENGINE
327 Author
: Date
:
2004 LAND CRUISER (RM1071U)
4 Check resistance of heated oxygen sensor heater.
PREPARATION:
Disconnect the H5, H6, H7 or H8 heated oxygen sensor con-
nector.
CHECK:
Measure resistance between terminals of the heated oxygen
sensor.
OK:
Tester ConnectionSpecified Condition
HT (H5-1) - +B (H5-2)11 to 16 W (20°C)
HT (H6-1) - +B (H6-2)11 to 16 W (20°C)
HT (H7-1) - +B (H7-2)11 to 16 W (20°C)
HT (H8-1) - +B (H8-2)11 to 16 W (20°C)
NG Replace heated oxygen sensor.
OK
5 Check EFI or ECD relay.
PREPARATION:
Remove the EFI or ECD relay from the engine room R/B.
CHECK:
Inspect the EFI or ECD relay.
OK:
Terminal No.ConditionSpecified Condition
2 - 4ConstantContinuity
UsuallyNo Continuity
1 - 3Apply B+ between
terminals 2 and 4Continuity
NG Replace EFI or ECD relay.
OK

A21339
E1 +B
OXHT
H5
H7
Components Side:
Bank1 Sensor1, Bank2 Sensor1
A21340
HT1A
OX1AE6
ECM ConnectorOX2A
HT2A
A21040
Reference (Bank 1 Sensor 1 System Drawing)
From
BatteryEFI or ECD
No. 1 FuseEFI or ECD
RelayEFI or ECD
No. 2 FuseHeater Oxygen
Sensor
Heater
SensorHT1A
OX1A
E2
MRELECM
- DIAGNOSTICSENGINE
DI-135
328 Author
: Date
:
2004 LAND CRUISER (RM1071U)
6 Check for open and short in harness and connector between ECM and heated
oxygen sensor (bank 1, 2 sensor 1).
PREPARATION:
(a) Disconnect the H5 or H7 heated oxygen sensor connec-
tor.
(b) Disconnect the E6 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Tester ConnectionSpecified Condition
OX (H5-3) - OX1A (E6-23)Below 1 W
HT (H5-1) - HT1A (E6-4)Below 1 W
OX (H7-3) - OX2A (E6-22)Below 1 W
HT (H7-1) - HT2A (E6-33)Below 1 W
OX (H5-3) or OX1A (E6-23) -
Body ground10 kW or higher
HT (H5-1) or HT1A (E6-4) -
Body ground10 kW or higher
OX (H7-3) or OX2A (E6-22) -
Body ground10 kW or higher
HT (H7-1) or HT2A (E6-33) -
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK

DI-136
- DIAGNOSTICSENGINE
329 Author
: Date
:
2004 LAND CRUISER (RM1071U)
7 Check whether misfire is occurred or not by monitoring DTC and data list.
NG Perform troubleshooting for misfire
(See page DI-167).
OK
8 Check air induction system (See page SF-1).
CHECK:
Check the air induction system for vacuum leaks.
NG Repair or replace air induction system.
OK
9 Check fuel pressure (See page SF-7).
CHECK:
Check the fuel pressure (high or low pressure).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF-1).
OK
10 Check injector injection (See page SF-24)
NG Replace injector.
OK

- DIAGNOSTICSENGINE
DI-137
330 Author
: Date
:
2004 LAND CRUISER (RM1071U)
11 Check exhaust system for gas leakage.
NG Repair or replace exhaust gas leakage point.
OK
Replace heated oxygen sensor (bank 1, 2 sensor 1).
12 Perform confirmation driving pattern (See page DI-106).
HINT:
Clear all DTCs prior to performing the confirmation driving pattern.
Go
13 Are there DTCs P0134 and P0154 being output again?
YES Replace ECM (See page SF-60).
NO
14 Confirm if vehicle has run out of fuel in past.
NO Check for intermittent problems
(See page DI-3).
YES
DTCs P0134 and P0154 are caused by running out of fuel.

DI-138
- DIAGNOSTICSENGINE
331 Author
: Date
:
2004 LAND CRUISER (RM1071U)
DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1
Sensor 2)
DTC P0156 Oxygen Sensor Circuit Malfunction (Bank 2
Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0031 on page DI-49.
DTC No.DTC Detecting ConditionTrouble Area
P0136
P0156
The following condition (a) or (b) continues 300 sec. or more.
(a) During driving with the engine warmed up, heated oxygen
sensor output does not change.
(b) Heated oxygen sensor output is very low most of the time.Open or short in heated oxygen sensor circuit
Heated oxygen sensor
Heated oxygen sensor heater
EFI or ECD relay
HINT:
Bank 1 refers to bank that includes cylinder No. 1.
Bank 2 refers to bank that does not includes cylinder No. 1.
Sensor 2 refers to the sensor farther away from the engine assembly.
MONITOR DESCRIPTION
The ECM monitors the rear heated oxygen sensor in the following 3 items:
(1) If the rear heated oxygen sensor voltage changes between Rich and Lean while the vehicle is
running (repeating acceleration and deceleration). If not, the ECM interprets this as a malfunc-
tion, illuminates the MIL, and then sets DTC.
(2) If the rear heated oxygen sensor voltage does not remain at less than 0.05 V for a long time while
the vehicle is running. If not, the ECM interprets this as a malfunction, illuminates the MIL, and
then sets DTC.
(3) If the sensor's voltage drops to below 0.2 V (extremely Lean status) immediately when the ve-
hicle decelerates and the fuel cut is working. if not, the ECM interprets this to mean the sensor's
response feature has deteriorated, illuminates the MIL, and then sets DTC.
DIC29-01

- DIAGNOSTICSENGINE
DI-139
332 Author
: Date
:
2004 LAND CRUISER (RM1071U)
MONITOR STRATEGY
Heated rear oxygen sensor output voltage
(Crack) (Bank 1)
P0136Heated rear oxygen sensor output voltage
(Bank 1)
RltdDTC
Heated rear oxygen sensor slow response
(Bank 1)
Related DTCsHeated rear oxygen sensor output voltage
(Crack) (Bank 2)
P0156Heated rear oxygen sensor output voltage
(Bank 2)
Heated rear oxygen sensor slow response
(Bank 2)
Rid / tMain sensors/componentsHeated rear oxygen sensorRequired sensors/componentsRelated sensors/componentsMass air flow meter, Vehicle speed sensor
Frequency of operationOnce per drive cycle
Duration300 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever the follow-
ing DTCs are not presentSee ºList of disable a monitorº (on page DI-3)
Case 1 (Output voltage (crack)):
Vehicle speed3 km/h (2 mph)-
IdleOFF
Fuel cutOFF
Time after fuel cut ON to OFF40 sec.-
Intake air amount per revolution0.7 g/rev-
Case 2 (Output voltage):
All of the following conditions are met:A, B, C and D
A. Pass/fail detection in this driving cycleNot detected
B. EngineRunning
C. Time after engine start0 sec.-
D. Either of the following conditions is
met:(a) or (b)
(a) Cumulative time while heated oxygen
sensor heater is ON22 sec.-
(b) At once more heated oxygen sensor
voltage0.2 V-
Case 3 (Slow response):
Rear oxygen sensor voltage before the
fuel cut0.2 V or more-
Catalyst conditionWarmed up
Engine coolant temperature75°C (167°F)-

DI-140
- DIAGNOSTICSENGINE
333 Author
: Date
:
2004 LAND CRUISER (RM1071U) Fuel cut
Operating
Time after engine start200 sec.-
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case 1 (Output voltage (crack)):
Following conditions are met:A, B and C
A. Cumulative rear heated oxygen sensor monitor time300 sec. or more
B. Time while rear heated oxygen sensor voltage is less
than 0.05 V180 sec. or more
C. Maximum rear heated oxygen sensor rich time (0.45 V or
more)Less than 20 sec.
Case 2 (Output voltage):
Number of heated oxygen sensor voltage ºswitchingº0 time or less
ºSwitchingº is counted when the sensor signal crosses the minimum or maximum voltage
Minimum voltageLess than 0.4 V
Maximum voltage0.5 V or more
Case 3 (Slow response):
Time until the rear oxygen sensor voltage drops to 0.2 V
after fuel cut starts operating6 sec. or more
COMPONENT OPERATING RANGE
ParameterStandard Value
Heated oxygen sensor voltage0 to 1 V
O2S TEST RESULT
Refer to page DI-3 for detailed information.
Rear HO2S voltage monitor
If the HO2S sensor voltage is out of the standard value, the ECM interprets this as a malfunction.
TEST IDDescription of TEST DATAConversion FactorUnit
$07Minimum rear HO2S voltageN/AV
$08Maximum rear HO2S voltageN/AV
If the time required to change is out of the standard value, the ECM interprets this as a malfunction.
TEST IDDescription of TEST DATAConversion FactorUnit
$31Time to change from Lean (<0.4 V)
to Rich (
0.5 V)N/Asec.
$32Time to change from Rich (
0.5
V) to Lean (<0.4 V)N/Asec.
Rear HO2S slow response monitor
If the elapsed time is out of the standard value, the ECM interprets this as a malfunction.
TEST IDDescription of TEST DATAConversion FactorUnit
$37Until rear HO2S voltage drops to
0.2 V after fuel-cut startingN/Asec.

A20316
Vehicle speed
40 km/h
(25 mph)
IG SW OFFOnce
40 sec.
or more
60 sec.
or more10 sec.Twice
40 sec.
or more12 times
40 sec.
or more
10 sec. 10 sec.
(
1)(
3)
(
4)
Idling(
2)(
3)
(
4)(
3)
(
4)
- DIAGNOSTICSENGINE
DI-141
334 Author
: Date
:
2004 LAND CRUISER (RM1071U)
Rear HO2S element monitor
If all the values ($81, $84, $85 and $87) are out of the standard values, the ECM interprets this as a malfunc-
tion.
TEST IDDescription of TEST DATAConversion FactorUnit
$81
Percentage of monitoring time
when the HO2S voltage is less
than 0.05 V
Multiply 0.3906%
$84
Percentage of monitoring time
when the HO2S voltage is more
than 0.7 V
Multiply 0.3906%
$85Time when the HO2S voltage is
0.45 V or moreMultiply 0.2621sec.
$87
Percentage of monitoring time
when the HO2S voltage is 0.45 V
or more
Multiply 0.3906%
WIRING DIAGRAM
Refer to DTC P0031 on page DI-49.
CONFIRMATION DRIVING PATTERN
1. Connect the hand-held tester to the DLC3. (
1)
2. Switch the hand-held tester from the normal mode to the check mode (See page DI-3). (
1)
3. Start the engine and let the engine idle for 60 seconds or more. (
2)
4. Drive the vehicle at 40 km/h (25 mph) or more for 40 seconds or more. (
3)
5. Let the engine idle for 10 seconds or more. (
4)
6. Perform steps 4. and 5. for 12 times.
HINT:
If a malfunction exists, the MIL will light up on the multi-information display during step 6.
NOTICE:
If the conditions in this test are not strictly followed, a malfunction detection will not occur. If you do
not have a hand-held tester, turn the ignition switch OFF after performing steps from 3 to 6, then per-
form steps from 3 to 6 again.