Toyota Corolla Repair Manual: 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
Engine coolant temperature circuit
Dtc p0115 engine coolant temperature circuit
Dtc p0117 engine coolant temperature circuit
low input
Dtc p0118 engine coolant temperature circuit
high input ...
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
Read freeze frame data using the hand-h ...
Other materials:
Overhaul
1. Remove manual transmission filler plug
Remove the manual transmission filler plug and gasket
from the manual transmission case.
2. Remove drain (mtm) plug sub–assy
Remove the drain (mtm) plug sub–assy and gasket from
the manual transmission case.
3. Remove speedometer se ...
Bluetooth® (Multimedia system)
Bluetooth®
■When using the Bluetooth® audio system
●In the following conditions, the system may not function.
• If the portable audio player is turned off
• If the portable audio player is not connected
• If the portable audio player’s battery is low
●There may be a delay if ...
Engine rear oil seal
Replacement
1. Remove manual transaxle assy (m/t transaxle)
2. Remove automatic transaxle assy (a/t transaxle)
3. Remove clutch cover assy (m/t transaxle)
remove the 6 bolts and clutch cover.
4. Remove clutch disc assy (m/t transaxle)
5. Remove flywheel sub–assy (m/t transaxle)
...