P0125

FA20 ENGINE CONTROL: SFI SYSTEM: P0125; Insufficient Coolant Temperature for Closed Loop Fuel Control; 2013 MY FR-S [03/2012 -]
P0125 - Insufficient Coolant Temperature for Closed Loop Fuel Control

DESCRIPTION

Refer to DTC P0117 P0117.





MONITOR DESCRIPTION

The diagnostic system monitors for a functional check of the engine coolant temperature sensor. If the engine coolant temperature does not reach the temperature to enable the closed loop air/fuel ratio control within a predetermined time after engine start, the diagnostic system determines a malfunction of engine coolant temperature sensor and stores the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on.

6. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

HINT
Check the engine coolant temperature is 20°C (68°F) or less at engine started.

7. Perform the following the confirmation driving pattern.

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

a. Drive the vehicle at 80 km/h (50 mph) or more for 20 minutes or more [A].

b. Stop the vehicle.

c. Idle the engine for 1 minute or more [B].

8. Enter the following menus: Powertrain / Engine / Trouble Codes.

9. Read pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

11. Input the DTC: P0125.

12. Check the DTC judgment result.





HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.

13. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0117 P0117.

INSPECTION PROCEDURE

HINT
* If any of DTCs P0116, P0117 or P0118 are set simultaneously with DTC P0125, the engine coolant temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.
* Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result:





HINT
If any DTCs other than P0125 are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART SFI System
A -- Continue to next step.

2. INSPECT THERMOSTAT

(a) Inspect the thermostat Testing and Inspection.

NG -- REPLACE THERMOSTAT Removal
OK -- Continue to next step.

3. CHECK COOLING SYSTEM

(a) Check for defects in the cooling system that might cause the system to be too cold, such as abnormal radiator fan operation or any modifications.

NG -- REPAIR OR REPLACE COOLING SYSTEM

OK -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal