TOYOTA LAND CRUISER 1998 Factory Repair Manual
Manufacturer: TOYOTA, Model Year: 1998, Model line: LAND CRUISER, Model: TOYOTA LAND CRUISER 1998Pages: 3115, PDF Size: 54.88 MB
Page 1121 of 3115
A19549
THA
E2ECM
2
1
Mass Air
Flow Meter Mass Air
Flow Meter
12
M1
THA E2
M1
DI-72
- DIAGNOSTICSENGINE
265 Author: Date:
2004 LAND CRUISER (RM1071U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the M1 mass air flow meter connector.
(b) Connect terminals 1 and 2 of the mass air flow meter wire
harness side connector.
(c) Turn the ignition switch ON.
(d) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: 1405C (2845F) or more
OK Confirm good connection at sensor. If OK, re-
place mass air flow meter.
NG
Page 1122 of 3115
A19548THA
E2
THA
E2ECM Mass Air Flow Meter
M1
E5
ECM Connector
A19550
THA
E2ECM Mass Air Flow
Meter
M1
- DIAGNOSTICSENGINE
DI-73
266 Author: Date:
2004 LAND CRUISER (RM1071U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Connect terminals THA and E2 of the E5 ECM connector.
HINT:
Before checking, do a visual and contact pressure checks for
the ECM connector.
(b) Turn the ignition switch ON.
(c) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: 1405C (2845F) or more
OK Repair or replace harness or connector.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page SF-60).
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the M1 mass air flow meter connector.
(b) Turn the ignition switch ON.
(c) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: -405C (-405F)
OK Replace mass air flow meter.
NG
Page 1123 of 3115
A19551A19635
ECM Mass Air Flow Meter
THA
E2 M1
E5
DI-74
- DIAGNOSTICSENGINE
267 Author: Date:
2004 LAND CRUISER (RM1071U)
5 Check for short in harness or ECM.
PREPARATION:
(a) Disconnect the E5 ECM connector.
(b) Turn the ignition switch ON.
(c) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / IN-
TAKE AIR.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: -405C (-405F)
OK Repair or replace harness or connector.
NG
Replace ECM (See page SF-60).
Page 1124 of 3115
- DIAGNOSTICSENGINE
DI-75
268 Author: Date:
2004 LAND CRUISER (RM1071U)
DTC P0115 Engine Coolant Temperature Circuit
DTC P0117 Engine Coolant Temperature Circuit Low
Input
DTC P0118 Engine Coolant Temperature Circuit High
Input
CIRCUIT DESCRIPTION
A thermistor is built in the Engine Coolant Temperature (ECT) sensor and changes the resistance value ac-
cording to the engine coolant temperature.
The structure of the sensor and connection to the ECM is the same the Intake Air Temperature (IAT) sensor.
HINT:
If the ECM detects the DTC ºP0115, P0117 or P0118º, it operates the fail-safe function in which the ECT
is assumed to be 80 C (176 F).
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0115Step 1
Open or short in engine cool-
ant temperature sensor circuit
for 0.5 sec.
P0117Step 4
Short in engine coolant tem-
perature sensor circuit for 0.5
sec.Open or short in engine coolant temperature sensor circuit
Engine coolant temperature sensor
ECM
P0118Step 2
Open in engine coolant tem-
perature sensor circuit for 0.5
sec.
HINT:
After confirming DTC ºP0115, P0117 or P0118,º use the OBD II scan tool or the hand-held tester to confirm
the engine coolant temperature from the DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
MONITOR DESCRIPTION
The ECT (Engine Coolant Temperature) sensor is used to monitor the engine coolant temperature. The ECT
sensor has a thermistor that varies its resistance depending on the temperature of the engine coolant. When
the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the
resistance drops. The variations in resistance are reflected in the voltage output from the sensor.
The ECM monitors the sensor voltage and uses this value to calculate the engine coolant temperature.
When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault
in the ECT sensor and sets a DTC.
Example:
When the ECM calculates that the ECT is less than -40C (-40F), or more than 140C (284F), and if either
the condition continues for 0.5 sec. or more, the ECM will set a DTC.
DI1LF-13
Page 1125 of 3115
DI-76
- DIAGNOSTICSENGINE
269 Author: Date:
2004 LAND CRUISER (RM1071U)
MONITOR STRATEGY
P0115Engine coolant temperature sensor range check
(Fluttering)
Related DTCsP0117Engine coolant temperature sensor range check
(Low resistance)
P0118Engine coolant temperature sensor range check
(High resistance)
Required sensors/componentsEngine coolant temperature sensor
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
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
P0115:
Engine coolant temperature sensor resistance
(Coolant temperature)Less than 79 W or more than 156 kW
(More than 140C (284F) or less than -40C (-40F))
P0117:
Engine coolant temperature sensor resistance
(Coolant temperature)Less than 79 W
(More than 140C (284F))
P0118:
Engine coolant temperature sensor resistance
(Coolant temperature)More than 156 kW
(Less than -40C (-40F))
COMPONENT OPERATING RANGE
ParameterStandard Value
Engine coolant temperature sensor resistance79 W (140C (284F)) to 156 kW (-40C (-40F))
Page 1126 of 3115
A19963
2
1G-B
BR-W
E528 E5 19
THW
E2
E1 R 5V ECM
BR E 2
Engine Coolant Temp. Sensor
3
If1
- DIAGNOSTICSENGINE
DI-77
270 Author: Date:
2004 LAND CRUISER (RM1071U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs related to different system that have terminal E2 as the ground terminal are output simulta-
neously, terminal E2 may have an open circuit.
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 determine 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.
Page 1127 of 3115
DI-78
- DIAGNOSTICSENGINE
271 Author: Date:
2004 LAND CRUISER (RM1071U)
1 Connect OBD II scan tool or hand-held tester, and read value of engine coolant
temperature.
PREPARATION:
(a) Connect the OBD II scan tool or the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or hand-held tester main switch ON.
(c) When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the hand-held tester.
OK:
Same value as actual engine coolant temperature.
RESULT:
Temperature DisplayedProceed to
-40°C (-40°F)A
140°C (284°F) or moreB
OK (Same as present temperature)C
HINT:
If there is an open circuit, OBD II scan tool or hand-held tester indicates -40°C (-40°F).
If there is a short circuit, OBD II scan tool or hand-held tester indicates 140°C (284°F) or more.
B Go to step 4.
C Check for intermittent problems
(See page DI-3).
A
Page 1128 of 3115
A19552
Engine Coolant
Temp. Sensor
2
1THW
E2ECM
E2
- DIAGNOSTICSENGINE
DI-79
272 Author: Date:
2004 LAND CRUISER (RM1071U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the E2 engine coolant temperature (ECT)
sensor connector.
(b) Connect terminals 1 and 2 of the engine coolant tempera-
ture sensor wire harness side connector.
(c) Turn the ignition switch ON.
(d) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL /
COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: 1405C (2845F) or more
OK Confirm good connection at sensor. If OK, re-
place engine coolant temperature sensor.
NG
Page 1129 of 3115
A19548
Engine Coolant
Temp. Sensor
ECM
E2 THW
E2 THW
E2
E5
ECM Connector
A19550
Engine Coolant
Temp. Sensor
ECM
2
1
E2 THW E2
DI-80
- DIAGNOSTICSENGINE
273 Author: Date:
2004 LAND CRUISER (RM1071U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the E2 engine coolant temperature sensor
connector.
(b) Connect terminals THW and E2 of the E5 ECM connector.
HINT:
Before checking, do a visual and contact pressure checks for
the ECM connector.
(c) Turn the ignition switch ON.
(d) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL /
COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: 1405C (2845F) or more
OK Repair or replace harness or connector.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page SF-60).
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the E2 engine coolant temperature sensor
connector.
(b) Turn the ignition switch ON.
(c) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL /
COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: -405C (-405F)
OK Replace engine coolant temperature sensor.
NG
Page 1130 of 3115
A19551A19635
ECM Engine Coolant
Temp. Sensor
E2 THW
E5
ECM Connector
- DIAGNOSTICSENGINE
DI-81
274 Author: Date:
2004 LAND CRUISER (RM1071U)
5 Check for short in harness or ECM.
PREPARATION:
(a) Disconnect the E5 ECM connector.
(b) Turn the ignition switch ON.
(c) When using hand-held tester, enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL /
COOLANT TEMP.
CHECK:
Read the temperature value on the OBD II scan tool or the
hand-held tester.
OK:
Temperature value: -405C (-405F)
OK Repair or replace harness or connector.
NG
Replace ECM (See page SF-60).