Troubleshooting
DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROLCIRCUIT DESCRIPTION
A thermistor built in the water temperature sensor changes the resistance value according to the water temperature.
The structure of the sensor and connection to the ECM is the same as the those of the air temperature sensor.
CONFIRMATION DRIVING PATTERN
a. Switch the hand-held tester from the normal mode to the check mode. *1
b. Start the engine and idle the engine for 100 seconds or more. *2
c. Drive the vehicle at 40 km/h (24 mph) or more for 20 seconds or more. *3
d. Idle the engine for 20 seconds or more. *4
e. Repeat the steps (c) and (d) 3 times.
f. Idle the engine for 30 seconds. *5
g. Check the 02 sensor output voltage.
HINT: If a malfunction exists, the malfunction indicator light comes on.
NOTE: If the conditions on this test are not strictly followed, the malfunction will not be detected.
Wiring Diagram:
Step 1 - 3:
Step 4 - 9:
Step 10 - 12:
INSPECTION PROCEDURE
HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, this 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.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
By putting the vehicle's ECM in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTCs.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.