TOYOTA LAND CRUISER 1998 Factory Repair Manual
Page 1101 of 3115
DI-52
- DIAGNOSTICSENGINE
245 Author: Date:
MONITOR STRATEGY
P0031Heated oxygen sensor heater current bank 1
sensor 1 (Low current)
P0032Heated oxygen sensor heater current bank 1
sensor 1 (High current)
P0037Heated oxygen sensor heater current bank 1
sensor 2 (Low current)
P0038Heated oxygen sensor heater current bank 1
sensor 2 (High current)
Related DTCs
P0051Heated oxygen sensor heater current bank 2
sensor 1 (Low current)
P0052Heated oxygen sensor heater current bank 2
sensor 1 (High current)
P0057Heated oxygen sensor heater current bank 2
sensor 2 (Low current)
P0058Heated oxygen sensor heater current bank 2
sensor 2 (High current)
Rid / tMain sensors/componentsHeated oxygen sensorRequired sensors/componentsRelated sensors/componentsVehicle speed sensor
Frequency of operationContinuous
Duration0.3 sec.
MIL tiP0031, P0037, P0051, P0057: 1 driving cycleMIL operationP0032, P0038, P0052, P0058: Immediate
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)
P0031, P0037, P0051, P0057 (Low current):
Either of the following conditions is met:A or B
A. Following conditions are met:1, 2, 3, 4 and 5
1. Time after engine start250 sec.500 sec.
2. Battery voltage10.5 V-
3. Vehicle speed-90 km/h (56 mph)
4. MisfireNot detected
5. Pass/Fail detection in this driving cycleNot detected
B. Following conditions are met:1, 2, 3, 4 and 5
1. Time after engine start500 sec.-
2. Battery voltage10.5 V-
3. Vehicle speed40 km/h (25 mph)-
4. MisfireNot detected
5. Pass/Fail detection in this driving cycleNot detected
P0032, P0038, P0052, P0058 (High current):
Intrusive heating is OFF
Page 1102 of 3115
- DIAGNOSTICSENGINE
DI-53
246 Author: Date:
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0031, P0037, P0051, P0057 (Low current):
Heated oxygen sensor heater currentLess than 0.25 A (at 0.3 sec. after heater ºONº)
P0032, P0038, P0052, P0058 (High current):
Heated oxygen sensor heater currentMore than 2.0 A (while intrusive heating is OFF)
COMPONENT OPERATING RANGE
ParameterStandard Value
Heated oxygen sensor heater current under the following
conditions:
(a) Engine has been warmed up
(b) Engine is idling
(c) Battery voltage is 11 to 14 V
0.4 to 1.0 A
MONITOR RESULT
The detailed information is described in CHECKING MONITOR STATUSº (see page DI-3).
TID (Test Identification) is assigned to each emission-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) is assigned to each test value.
Unit Conversion is used to calculate the test value indicated on generic OBD scan tools.
TID $04: HO2S Heater
TLTCIDUnit ConversionDescription of Test ValueDescription of Test Limit
1$01Multiply by 0.000076 (A)Maximum HO2S heater current (bank 1 sensor 1)Malfunction criterion
1$02Multiply by 0.000076 (A)Maximum HO2S heater current (bank 1 sensor 2)Malfunction criterion
1$10Multiply by 0.000076 (A)Maximum HO2S heater current (bank 2 sensor 1)Malfunction criterion
1$20Multiply by 0.000076 (A)Maximum HO2S heater current (bank 2 sensor 2)Malfunction criterion
Page 1103 of 3115
A21367
ECM
MREL
E2
HT2A
OX2A
OX1A HT1A
HT2B
OX2B
OX1B HT1B 8
28
33
22
234
25
21
295 E9
E5
E6
E6
E6E6
E6
E6
E6 E6 J/B No. 5
2 15
5C
5D B-W
1
1 1
1
12
3 4 Engine Room R/B
EFI or ECD Relay
W-B
B-Y
B-Y
B-Y
1
IX2SB
Cowl Side J/B LH
EFI or ECD No. 245
5
2A2Q
Engine Room J/B
43 44
11
1
1C 1A 1B
1BEFI or ECD No. 1
F15
FL Block
291 2
3
43
8119 5
11 2
3
41
43
1
3 2
43B-W
EB3
EB3
EB3 EB3 EB3
EB3
EB1BR
BR
BRBR B-G
EA ECD C C C C C J17
J/C
MAIN
BatteryW-B+B
E1HT
OX HT
OX +B
E1H7 Heated Oxygen Sensor
(Bank 2 Sensor 1)
H5 Heated Oxygen Sensor
(Bank 1 Sensor 1)If1
B W
W
BY
W
B LL (*1)
(*1)
(*1)
(*1) (*1)
(*1)BR-W BR-W
B-Y
B-Y
B-Y
W-B
B-YR-B R-B
+B
E1HT
OXHT
OX +B
E1
BR-WH6 Heated Oxygen Sensor
(Bank 1 Sensor 2)
D
*1: Shielded H8 Heated Oxygen Sensor
(Bank 2 Sensor 2)R B-Y
2
BR-W
BR-W BR-W
BR-W BR-W BR-W
B-Y
B-Y
B-Y DI-54
- DIAGNOSTICSENGINE
247 Author: Date:
WIRING DIAGRAM
Page 1104 of 3115
A20870
E1 +B
OX
+BHT
OX E1HT H5
H7
H6
H8
Components Side:
Bank1 Sensor1, Bank2 Sensor1
Bank1 Sensor2, Bank2 Sensor2
- DIAGNOSTICSENGINE
DI-55
248 Author: Date:
INSPECTION PROCEDURE
HINT:
Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the en-
gine conditions when the malfunction is detected. When troubleshooting, it is useful to determine 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.
1 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
Page 1105 of 3115
A21543
1
23
4 EFI or ECD Relay
A19522A19630
HT1A HT1BE6
ECM Connector HT2A
HT2B
DI-56
- DIAGNOSTICSENGINE
249 Author: Date:
2 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
3 Check voltage between terminals HT1A, HT2A, HT1B, HT2B of ECM connectors
and body ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals of the ECM connectors
and body ground.
HINT:
Connect terminal HT1A to the bank 1 sensor 1.
Connect terminal HT1B to the bank 1 sensor 2.
Connect terminal HT2A to the bank 2 sensor 1.
Connect terminal HT2B to the bank 2 sensor 2.
OK:
Tester ConnectionSpecified Condition
HT1A (E6-4) - Body ground9 to 14 V
HT1B (E6-5) - Body ground9 to 14 V
HT2A (E6-33) - Body ground9 to 14 V
HT2B (E6-25) - Body ground9 to 14 V
OK Replace ECM (See page SF-60).
NG
Check and repair harness or connector between EFI or ECD relay and heated oxygen sensor, and
heated oxygen sensor and ECM (See page IN-36).
Page 1106 of 3115
FI6929A09074A09707
Power Transistor
Output
Voltage
AB B+
Temperature Sensor
Platinum Hot Wire
Temperature Sensor
Platinum Hot Wire
- DIAGNOSTICSENGINE
DI-57
250 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC P0100 Mass or Volume Air Flow Circuit
DTC P0102 Mass or Volume Air Flow Circuit Low Input
DTC P0103 Mass or Volume Air Flow Circuit High Input
CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses
this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MAF meter,
there is a heated platinum wire exposed to the flow of intake air.
By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incom-
ing air cools the wire and an internal thermistor, affecting their resistance. To maintain a constant current
value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is pro-
portional to the airflow through the sensor. The ECM interprets this voltage as the intake air amount.
The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No.DTC Detection ConditionTrouble Area
P0100Open or short in mass air flow meter circuit for more than 3
sec.
P0102Open or short in mass air flow meter circuit for more than 3
sec.Open or short in mass air flow meter circuit
Mass air flow meter
P0103
Open in mass air flow meter circuit for more than 3 sec. (EVG
circuit)
Short in mass air flow meter circuit for more than 3 sec. (+B
circuit)Mass air flow meter
ECM
DIC23-01
Page 1107 of 3115
DI-58
- DIAGNOSTICSENGINE
251 Author: Date:
2004 LAND CRUISER (RM1071U)
HINT:
After confirming DTC P0100, P0102 or P0103, use the hand-held tester or the OBD II scan tool to confirm
the MAF ratio from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL).
Mass Air Flow Value (gm/sec.)Malfunction
Approx. 0.0Mass air flow meter power source circuit open
VG circuit open or short
271.0 or moreEVG circuit open
MONITOR DESCRIPTION
If there is a defect in the MAF (Mass Air Flow) meter or an open or short circuit, the voltage level will deviate
outside the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets
a DTC.
Example:
When the MAF meter voltage output is less than 0.2 V, or more than 4.9 V, and if either the condition contin-
ues for more than 3 sec.
MONITOR STRATEGY
P0100Mass air flow meter circuit range check
(Fluttering)
Related DTCsP0102Mass air flow meter circuit range check
(Low voltage)
P0103Mass air flow meter circuit range check
(High voltage)
Required sensors/componentsMass air flow meter
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (When engine speed is at less than 4,000 rpm)
2 driving cycles (When engine speed is at 4,000 rpm or more)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever the follow-
ing DTCs are not presentSee ºList of disable a monitorº (on page DI-3)
The typical enabling condition is not avail-
able-
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0100:
Mass air flow meter voltageLess than 0.2 V or more than 4.9 V
P0102:
Mass air flow meter voltageLess than 0.2 V
P0103:
Mass air flow meter voltageMore than 4.9 V
Page 1108 of 3115
A21361
ECM
MRELVG
E2G
8 E530
E5 29 M1
Mass Air Flow Meter
Battery EFI or ECD No. 2
B-YCowl Side J/B LH
10 5
2A
2BB-YVG
E2G +B
34 5
G-W G-W G-WL-Y
L-Y L-Y
IW3
IW3IN2
IN2
E9 B-W B-WJ/B No. 5
15 2
5D 5C
W-B
Engine Room R/B
EFI or ECD Relay
1
1 1
1
1 2
34Engine Room J/B
4443
1B 1A
1B 1CW-B W-B
B-Y W-B
B-Y
F15
FL Block
MAIN2B-G
EA 1 11EFI or ECD No. 168
2 5
- DIAGNOSTICSENGINE
DI-59
252 Author: Date:
2004 LAND CRUISER (RM1071U)
COMPONENT OPERATING RANGE
ParameterStandard Value
Mass air flow meter voltage0.4 to 2.2 V
WIRING DIAGRAM
Page 1109 of 3115
DI-60
- DIAGNOSTICSENGINE
253 Author: Date:
2004 LAND CRUISER (RM1071U)
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 Connect OBD II scan tool or hand-held tester, and read value of mass air flow
rate.
PREPARATION:
(a) Connect the OBD II scan tool or hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or the hand-held tester main switch ON.
(c) Start the engine.
(d) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / MAF.
CHECK:
Read the mass air flow rate on the OBD II scan tool or the hand-held tester.
RESULT:
Air Flow Rate (gm/s)Proceed to
0.0A
271.0 or moreB
Between 1 and 270.0 (*1)C
*1: The value must be changed when the throttle valve is opened or closed.
B Go to step 6.
C Check for intermittent problems
(See page DI-3).
A
Page 1110 of 3115
A21226
Wire Harness Side:
+B
Mass Air Flow Meter Connector
M1
A19522A19630
VG E5ECM Connector E2G
- DIAGNOSTICSENGINE
DI-61
254 Author: Date:
2004 LAND CRUISER (RM1071U)
2 Check voltage of mass air flow meter power source.
PREPARATION:
(a) Disconnect the M1 mass air flow meter connector.
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminal of the mass air flow meter
connector and body ground.
OK:
Tester ConnectionSpecified Condition
+B (M1-3) - Body ground9 to 14 V
NG Go to step 5.
OK
3 Check voltage between terminal VG of ECM connector and body ground.
PREPARATION:
Start the engine.
CHECK:
Measure the voltage between the specified terminal of the E5
ECM connector.
HINT:
The shift position should be P or N and the A/C switch should
be turned OFF.
OK:
Tester ConnectionConditionSpecified Condition
VG (E5-30) -
E2G (E5-29)Engine is idling0.5 to 3.0 V
OK Replace ECM (See page SF-60).
NG