DTC Description
DTC DETECTION LOGIC
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough.
This is due to a leak in the seal or the thermostat being stuck open.
DTC No. | CONSULT screen terms (Trouble diagnosis content) | DTC detecting condi |
P0128 | THERMSTAT FNCTN [Coolant thermostat (coolant temperature below thermostat regulating temperature)] | The engine coolant temperature does not reach to specified temperature even though the engine has run long enough. |
POSSIBLE CAUSE
FAIL-SAFE
Not applicable
DTC CONFIRMATION PROCEDURE
NOTE: Never refuel before and during the following procedure.
1.CHECK DTC PRIORITY
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303 or P0304.
Is applicable DTC detected? YES >> Perform diagnosis of applicable. Refer to EC-93, "DTC Index".
NO >> GO TO 2.
2.PRECONDITIONING-1
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 3.
3.PRECONDITIONING-2
With CONSULT
Ambient temperature | −10°C (14°F) or more |
A/C switch | OFF |
Blower fan switch | OFF |
COOLAN TEMP/S | −10°C – 58°C (14 – 136°F) |
Is the condition satisfied? YES >> GO TO 4.
NO >> 1. Satisfy the condition.
2. GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE-1
With CONSULT
CAUTION: Always drive vehicle at safe speed.
STEP 1
Drive the vehicle under the conditions instructed below until the difference between “COOLAN TEMP/S” and “FUEL T/TMP SE” becomes at least 26°C (47°F).
COOLAN TEMP/S | 66°C (151°F) or less |
FUEL T/TMP SE | Less than the value calculated by subtracting 26°C (47°F) from “COOLAN TEMP/S”.* |
*: Example
COOLAN TEMP/S | FUEL T/TMP SE |
70°C (158°F) | 44°C (111°F) or less |
65°C (149°F) | 39°C (102°F) or less |
60°C (140°F) | 34°C (93°F) or less |
STEP 2
Drive the vehicle at 50 km/h (32 MPH) or more with the difference between “COOLAN TEMP/S” and “FUEL T/TMP SE” maintained at 26°C (47°F) or more.
NOTE: Keep the accelerator pedal as steady as possible during cruising.
STEP 3
Drive the vehicle at 50 km/h (32 MPH) or more until “COOLAN TEMP/S” increases by 6°C (11°F).
NOTE: Keep the accelerator pedal as steady as possible during cruising. Is the condition satisfied? YES >> GO TO 5.
NO >> GO TO 2.
5.PERFORM DTC CONFIRMATION PROCEDURE-2
With CONSULT
COOLAN TEMP/S | 67°C (153°F) or more |
CAUTION: Always drive vehicle at safe speed.
Is 1st trip DTC detected? YES >> Proceed to EC-224, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK DTC PRIORITY
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303 or P0304, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303 or P0304.
Is applicable DTC detected? YES >> Perform diagnosis of applicable. Refer to EC-93, "DTC Index".
NO >> GO TO 2.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Check the engine coolant temperature sensor. Refer to EC-225, "Component Inspection".
Is the inspection result normal? YES >> GO TO 3.
NO >> Replace engine coolant temperature sensor. Refer to CO-23, "Exploded View".
3.CHECK THERMOSTAT
Check the thermostat. Refer to CO-21, "Removal and Installation".
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace thermostat.
Component Inspection
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor. Refer to CO-23, "Exploded View".
Basic inspection
DIAGNOSIS AND REPAIR WORK FLOW
Work Flow
OVERALL SEQUENCE
DETAILED FLOW
1.GET INFORMATION FOR SYMPTOM
Get detailed information from the customer about the symptom (the
condition and the environment when
the incident/malfunction occurs).
Check operation condition of the ...
Connector Symbols
Most of connector symbols in wiring diagrams are shown from the terminal
side.
Connector symbols shown from the terminal side are enclosed by
a single line and followed by the direction mark.
Connector symbols shown from the harness side are enclosed by
a double line and foll ...
Front wiper motor lo circuit
Component Function Check
1.CHECK FRONT WIPER LO OPERATION
CONSULT ACTIVE TEST
Select FR WIPER of BCM (WIPER) active test item.
Check front wiper operation.
LO : Front wiper (LO) operation
OFF : Front wiper OFF
Is the inspection result normal?
YES >> Front wiper motor ...