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:
Hydraulic test
1. Perform hydraulic test
Measure the line pressure.
Notice:
Do the test at normal operation atf temperature 50 to 80 °c (122 to
176 °f).
The line pressure test should always be carried out in pairs. One
technician should observe
the conditions of wheels or wheel stopper outsi ...
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished).
Perform active test using hand–held tester (a/f control).
Hint:
”a/f control” is the active te ...
On–vehicle inspection
1. Check basic function (manual operation function)
turn the ignition switch on.
Check that the door glass moves up when each window switch of the
regulator master switch
assembly is turned up and moves down when each window switch is turned down.
Check that the do ...


