Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Insufficient coolant temperature
for closed loop fuel control / Inspection procedure
Toyota Corolla (E120): Inspection procedure
Hint
:
- if dtcs p0115, p0116, p0117, p0118 and p0125 are output simultaneously, the engine coolant temperature sensor circuit may be open or short. Perform the troubleshooting of dtc p0115, p0117 or p0118 first.
- 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, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Check other dtc output(in addition to dtc p0125)
- Connect the hand–held tester or the obd ii scan tool to the dlc3.
- turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.
- select the item ”diagnosis / enhanced obd ii / dtc info / current codes”.
- read the dtcs.
Result:

Hint
: if any other codes besides p0125 are output, perform the troubleshooting for those dtcs first.


2 Inspect thermostat


Replace engine coolant temperature sensor
Other materials:
Data list/active test
1. Data list
Hint:
using the data list displayed by the hand–held tester or the obd ii scan tool,
you can read the value of
the switches, sensors, actuators and so on without parts removal. Reading the
data list as a first step
of troubleshooting is one method to shorten diagnostic time.
...
Inspection
1. Inspect inner rear view mirror assy
Inspect the electro chromic inner mirror operation.
Connect the positive (+) lead from the battery to terminal
1 and negative (–) lead to terminal 2.
) Attach black colored tape to the forward sensor to
prevent it from sensing.
&nb ...
Inspection
1. Headlamp dimmer switch assy
Inspect light control switch continuity.
Measure the resistance according to the value(s) in
the table below.
Standard:
Inspect headlight dimmer switch continuity.
Measure the resistance according to the value(s) in
the tabl ...


