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DTC Description
 
 
DTC DETECTION LOGIC
DTCM.U.T.-III SE screen terms
(Trouble diagnosis content)
DTC detection condition
P012500ECT SENSOR
(Insufficient coolant temperature for closed loop fuel control)
Diagnosis condition—
Signal (terminal)Engine coolant temperature sensor signal
Threshold
  • Voltage sent to ECM from the engine coolant temperature sensor is not practical, even when some time has passed after starting the engine
  • Engine coolant temperature sensor is insufficient for closed loop fuel control
Diagnosis delay time—
 
 
POSSIBLE CAUSE
  • Harness or connectors (High resistance in the engine coolant temperature sensor circuit)
  • Engine coolant temperature sensor
  • Multi-way control valve
 
 
FAIL-SAFE
Not applicable
 
 
DTC Confirmation Procedure
1.CHECK DTC PRIORITY
If DTC P0125 is displayed with P0116, P0117 or P0118, first perform the trouble diagnosis for DTC P0116, P0117 or P0118.
Is applicable DTC detected?
Perform diagnosis of applicable.
.
 
2.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds.
: .
 
3.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
With M.U.T.-III SE
  1. Turn ignition switch ON.
  2. Select “DATA MONITOR” mode of “ENGINE” using M.U.T.-III SE.
  3. Check that “COOLANT TEMP/S” is above 10°C (50°F).
 
With GST
Follow the procedure “With M.U.T.-III SE” above.
 
Is it above 5°C (41°F)?
INSPECTION END
.
 
4.PERFORM DTC CONFIRMATION PROCEDURE
With M.U.T.-III SE
  1. Start engine and run it for 65 minutes at idle speed.
  2. Check 1st tip DTC.
If “COOLANT TEMP/S” indication increases to more than 10°C (50°F) within 65 minutes, stop engine because the test result will be OK.
cautionBe careful not to overheat engine.
 
With GST
Follow the procedure “With M.U.T.-III SE” above.
 
Is 1st trip DTC detected?
Proceed to DTC Diagnosis Procedure.
-1To check malfunction symptom before repair: Refer to Intermittent IncidentIntermittent Incident.
-2Confirmation after repair: INSPECTION END