Toyota Tundra. Manual — part 1343

TYPICAL MALFUNCTION THRESHOLDS

After engine stop:

TYPICAL MALFUNCTION THRESHOLDS - AFTER ENGINE STOP

After cold engine start:

TYPICAL MALFUNCTION THRESHOLDS - AFTER COLD ENGINE START

WIRING DIAGRAM

Refer to DTC P0110 .

INSPECTION PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0111)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

e. Read DTCs.

Result

RESULT REFERENCE

HINT:

If any DTCs other than P0111 are output, troubleshoot those DTCs first.

B : REPLACE MASS AIR FLOW METER (See REMOVAL )

A : GO TO DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )

Either of the following conditions 1 or 2 is met:

-

1. Duration while engine load is low

120 seconds or more

2. Duration while engine load is high

10 seconds or more

IAT change

Less than 1°C (2°F)

IAT change

Less than 1°C (2°F)

Result

Proceed To

P0111 and other DTCs are output

A

P0111 is output

B

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

DTC P0115 ENGINE COOLANT TEMPERATURE CIRCUIT MALFUNCTION; DTC P0117 ENGINE
COOLANT TEMPERATURE CIRCUIT LOW INPUT; DTC P0118 ENGINE COOLANT
TEMPERATURE CIRCUIT HIGH INPUT

DESCRIPTION

A thermistor, whose resistance value varies according to the ECT, is built into the Engine Coolant Temperature
(ECT) sensor.

The structure of the sensor and its connection to the ECM are the same as those of the Intake Air Temperature
(IAT) sensor.

HINT:

When any of DTCs P0115, P0117 and P0118 are set, the ECM enters fail-safe mode. During fail-safe mode, the
ECT is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

DTC DETECTION CONDITION AND TROUBLE AREA

HINT:

When any of these DTCs are set, check the ECT by entering the following menus: Powertrain/Engine and
ECT/Data List/All Data/Coolant Temp.

TEMPERATURE SPECIFICATION

MONITOR DESCRIPTION

The Engine Coolant Temperature (ECT) sensor is used to monitor the ECT. The ECT sensor has a thermistor

DTC

Code

DTC Detection Condition

Trouble Area

P0115

Open or short in ECT sensor circuit for 0.5 seconds (1 trip
detection logic)



Open or short in ECT sensor
circuit



ECT sensor



ECM

P0117

Short in ECT sensor circuit for 0.5 seconds (1 trip
detection logic)



Short in ECT sensor



ECT sensor



ECM

P0118

Open in ECT sensor circuit for 0.5 seconds (1 trip
detection logic)



Open in ECT sensor circuit



ECT sensor



ECM

Temperature Displayed

Malfunction

-40°C (-40°F)

Open circuit

140°C (284°F) or higher

Short circuit

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

with a resistance that varies according to 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. These
variations in resistance are reflected in the output voltage from the sensor. The ECM monitors the sensor
voltage and uses this value to calculate the ECT. 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:

If the sensor output voltage is more than 4.91 V for 0.5 seconds or more, the ECM determines that there is an
open in the ECT sensor circuit, and sets DTC P0118. Conversely, if the voltage output is less than 0.14 V for
0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and sets DTC P0117.

If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

P0115:

TYPICAL MALFUNCTION THRESHOLDS - P0115

P0117:

TYPICAL MALFUNCTION THRESHOLDS - P0117

P0118:

Related DTCs

P0115: ECT sensor range check (Fluctuating)
P0117: ECT sensor range check (Low voltage)
P0118: ECT sensor range check (High voltage)

Required Sensors/Components (Main)

ECT sensor

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

0.5 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs not present

None

ECT sensor voltage

Less than 0.14 V, or higher than 4.91 V

ECT sensor voltage [ECT]

Less than 0.14 V [More than 140°C (284°F)]

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

TYPICAL MALFUNCTION THRESHOLDS - P0118

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

WIRING DIAGRAM

Fig. 70: Engine Coolant Temperature Circuit Malfunction - Wiring Diagram

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the Techstream. Freeze frame data records the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was
moving or stationary, 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. READ OUTPUT DTC

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON and turn the Techstream ON.

c. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

d. Read DTCs.

Result

RESULT REFERENCE

ECT sensor voltage [ECT]

Higher than 4.91 V [Less than -40°C (-40°F)]

ECT sensor voltage [ECT]

0.14 to 4.91 V [-40 to 140°C (-40 to 284°F)]

Result

Proceed To

P0115 is output

A

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra