Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Engine coolant temperature circuit / Circuit description
Toyota Corolla (E120): Circuit description
A thermistor is built in the engine coolant temperature sensor and changes the resistance value according to the engine coolant temperature.
The structure of the sensor and connection to the ecm is the same as those of the intake air temperature sensor.
Hint
: if the ecm detects the dtc p0115, p0117 or p0118, it operates the fail–safe function in which the engine coolant temperature is assumed to be 80 c (176 °F).
|
Dtc no. |
Proceed to |
Dtc detection condition |
Trouble area |
| P0115 | Step 1 | Open or short in engine coolant temperature sensor circuit for 0.5 Seconds |
|
| P0117 | Step 4 | Short in engine coolant temperature sensor circuit for 0.5 Seconds | |
| P0118 | Step 2 | Open in engine coolant temperature sensor circuit for 0.5 Seconds |
Hint
: after confirming dtc p0115, p0117 or p0118, confirm the engine coolant temperature in the ”diagnosis/ enhanced obd ii/data list/all” using the hand–held tester or the obd ii scan tool.
Monitor description
The engine coolant temperature (ect) 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 –40 c (–40 °F), or more than 140 c (284 °F), and if either the condition continues for 0.5 Sec or more, the ecm will set a dtc.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating range
Wiring diagram
Other materials:
Opening the trunk
■ Trunk opener
Pull the lever upward to release
the trunk lid.
■ Trunk release button (vehicles
with a smart key system)
While carrying the electronic
key, press the button on the
trunk lid.
When all the doors are unlocked
using one of the following methods,
the trunk can be opened
without the ...
Power door lock control system
Symptom
Suspected area
All doors are not operated by driver’s door key cylinder
interlocked with key
Door lock control switch
Front door lock assy lh
Wire harness
Integration relay
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Using the radio
Radio operation
Select “AM” or “FM” to begin listening to the radio.
1 Power
2 Volume
3 Station selectors
4 Adjust frequency or select an item
5 AM/FM mode button
6 Scan for receivable stations
7 Seek a frequency
Setting station presets
1Search for a desired station by turning
...