TOYOTA CAMRY 1999 Service Repair Manual

A00393
ON
Intake Air Temp.
Sensor
2
1ECM
3
9
THA
E2
E15 V
E8
E8
± DIAGNOSTICSENGINE (5S±FE)
DI±39
274 Author: Date:
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the intake air temp. sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: ±40°C (±40°F)
OK Replace intake air temp. sensor.
NG

A03011A03410
Intake Air Temp.
SensorECM
THA
E25 V
E1
ON
E8 Connector
w/o Immobiliser
w/ Immobiliser
E8 Connector
DI±40
± DIAGNOSTICSENGINE (5S±FE)
275 Author: Date:
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Disconnect the E8 connector from the ECM.
HINT:
The intake air temp. sensor connector is disconnected.
(c) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: ±40°C (±40°F)

OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±41
276 Author: Date:
DTC P0115 Engine Coolant Temp. Circuit Malfunction

CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the engine
coolant temp.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunc-
tion shown on page DI±35.
If the ECM detects the DTC P0115, it operates fail safe function in which the engine coolant temperature
is assumed to be 80°C (176°F).
DTC No.Detection ItemTrouble Area
P0115Open or short in engine coolant temp. sensor circuit

Open or short in engine coolant temp. sensor circuit

Engine coolant temp. sensor

ECM
HINT:
After confirming DTC P0115, use the OBD II scan tool or TOYOTA hand±held tester to confirm the engine
coolant temp. from the CURRENT DATA.
Temp. DisplayedMalfunction
±40°C (±40°F)Open circuit
140°C (284°F) or moreShort circuit
DI00P±05

A00310
Engine Coolant Temp.
Sensor
2
1ECM
G±B
BR4
E8
E895 V
THW
E2
E1 R DI±42
± DIAGNOSTICSENGINE (5S±FE)
277 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.

A00395
ECM ON
Engine Coolant
Temp. Sensor
2
14
9
THW
E25 V
E1 E8
E8
± DIAGNOSTICSENGINE (5S±FE)
DI±43
278 Author: Date:
1 Connect OBD II scan tool or TOYOTA hand±held tester, and read value of
engine coolant temperature.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand±held tester main switch
ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA hand±held tester.
OK:
Same as actual engine coolant temperature
HINT:

If there is open circuit, OBD II scan tool or TOYOTA hand±held tester indicates ±40°C (±40°F).

If there is open circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG ±40°C (±40°F) ... Go to step 2.
140°C (284°F) or more ... Go to step 4.
OK
Check for intermittent problems
(See page DI±3).
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) Connect the sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Confirm good connection at sensor. If OK, re-
place engine coolant temp. sensor.
NG

A03012A03411
ON
4 Engine Coolant
Temp. Sensor
2
1ECM
THWE2
5 V
THW
E1 E8
E8
9E2
w/o Immobiliser
w/ Immobiliser
THW
E2
DI±44
± DIAGNOSTICSENGINE (5S±FE)
279 Author: Date:
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Connect between terminals THW and E2 of the ECM con-
nector.
HINT:
The engine coolant temp. sensor connector is disconnected.
Before checking, do a visual and contact pressure check for the
ECM connector (See page IN±31).
(c) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Open in harness between terminals E2 or THW,
repair or replace harness.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page IN±31).

A00397
ON
Engine Coolant
Temp. Sensor
4
9ECM
E8
E8THW
E25 V
E1
± DIAGNOSTICSENGINE (5S±FE)
DI±45
280 Author: Date:
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: ± 40°C (± 40°F)
OK Replace engine coolant temp. sensor.
NG

A03011A03412
Engine Coolant
Temp. Sensor
THW
E25 V
E1
ON
E8 Connector w/o Immobiliser
w/ Immobiliser
E8 Connector
DI±46
± DIAGNOSTICSENGINE (5S±FE)
281 Author: Date:
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Disconnect the E8 connector from the ECM.
HINT:
The engine coolant temp. sensor connector is disconnected.
(c) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: ±40°C (±40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±47
282 Author: Date:
DTC P0116 Engine Coolant Temp. Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0115 (Engine Coolant Temp. Circuit Malfunction) on page DI±41.
DTC No.DTC Detecting ConditionTrouble Area
If THW < ±7°C (19.4°F) or THA < ±7°C (19.4°F) 20 min. or
more after starting engine, engine coolant temp. sensor value
is 30°C (86°F)*1 20°C (48°F)*2 or less
(2 trip detection logic)
If THW ±7°C (19.4°F) and THA
±7°C (19.4°F) and 10°C
(50°F) at engine start, 5 min. or more after starting engine,
engine coolant temp. sensor value is 30°C (86°F)*1 20°C
(48°F)*2 or less
(2 trip detection logic)
P0116 If THW
10°C (50°F) and THA
10°C (50°F) at engine
start, 2 min. or more after starting engine, engine coolant temp.
sensor value is 30°C (86°F)*1 20°C (48°F)*2 or less
(2 trip detection logic)
Engine coolant temp. sensor

Cooling system
When THW 35°C (95°F) and 60°C (140°F), THA

±6.7°C (19.9°F) when starting the engine, condition (a) and
(b) continues:
(a) Vehicle speed is changing (Not stable)
(b) Water temperature change is lower than 3°C (37.4°F) from
the water temperature since when sterting the engine
(2 trip detection logic)
*1: Except California Specification vehicles.
*2: Only for California Specification vehicles.
INSPECTION PROCEDURE
HINT:

If DTCs P0115 (Engine Coolant Temp. Circuit Malfunction) and P0116 (Engine Coolant Temp. Circuit
Range/Performance Problem) are output simultaneously, engine coolant temp. sensor circuit may be
open. Perform troubleshooting of DTC P0115 first.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0116) being output?
YES Go to relevant DTC chart.
NO
DI00Q±05

DI±48
± DIAGNOSTICSENGINE (5S±FE)
283 Author: Date:
2 Check thermostat (See page CO±10).
NG Replace thermostat.
OK
Replace engine coolant temp. sensor.