ENGINE (DIAGNOSTICS)(H4DO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)
DTC P0118 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT HIGH
DTC detecting condition:
Immediately at fault recognition
Trouble symptom:
• Hard to start
• Improper idling
• Poor driving performance
CAUTION:
After servicing or replacing faulty parts, perform Clear Memory Mode Clear Memory Mode > OPERATION">, and Inspection Mode Inspection Mode > PROCEDURE">.
Wiring diagram:
Engine electrical system Engine Electrical System">
STEP | CHECK | YES | NO |
1.CHECK CURRENT DATA.
1) Start the engine.
2) Read the value of «Coolant Temp.» using the Subaru Select Monitor or a general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to “Current Data Display For Engine”. Subaru Select Monitor">
• General scan tool
For detailed operation procedures, refer to the general scan tool operation manual.
Is the value of «Coolant Temp.» −40°C (−40°F) or less?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0118 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT HIGH">Go to Step 2.
Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
NOTE:
In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2.CHECK FOR POOR CONTACT.
Check for poor contact of ECM and engine coolant temperature sensor connector.
Is there poor contact of ECM or engine coolant temperature sensor connector?
Repair the poor contact of ECM or engine coolant temperature sensor connector.
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0118 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT HIGH">Go to Step 3.
3.CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from the engine coolant temperature sensor.
4) Measure the resistance of harness between ECM connector and engine coolant temperature sensor connector.
Connector & terminal
(B134) No. 30 — (E8) No. 2:
(B134) No. 29 — (E8) No. 1:
Is the resistance less than 1 ??
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0118 ENGINE COOLANT TEMPERATURE SENSOR 1 CIRCUIT HIGH">Go to Step 4.
Repair the harness and connector.
NOTE:
In this case, repair the following item:
• Open circuit in harness between ECM connector and engine coolant temperature sensor connector
• Poor contact of coupling connector
4.CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR.
1) Connect all connectors.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM connector and chassis ground.
Connector & terminal
(B137) No. 30 (+) — Chassis ground (−):
Is the voltage 5 V or more?
Repair the short circuit of harness to power supply between ECM connector and engine coolant temperature sensor connector.
Replace the engine coolant temperature sensor. Engine Coolant Temperature Sensor">
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of the engine coolant temperature sensor.
Judge as NG if out of specification.
2. COMPONENT DESCRIPTION
(A) | Resistance value (k?) | (B) | Temperature °C (°F) | ||
(1) | Connector | (2) | Thermistor element |
3. EXECUTION CONDITION
Secondary Parameters | Execution condition |
None |
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
5. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Malfunction Criteria | Threshold Value |
Output voltage | ≥ 4.698 V |
Time Needed for Diagnosis: 500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
Removal
COOLING(H4DO) > Water Pipe AssemblyREMOVAL1. WATER PIPE ASSEMBLY RH1. Disconnect the ground cable from battery. NOTE">2. Drain engine coolant. Engine Coolant > REPLACEMENT">3. Remove the front exhaust pipe. Front Exhaust Pipe > REMOVAL">4. Disconnect the water hos ...
Wheel replacement
When replacing wheels due, for example,
to damage, make sure the replacement
wheels match the specifications of the
wheels that are fitted as standard equipment.
Replacement wheels are available
from SUBARU dealers.
WARNING
Use only those wheels that are
specified for your vehicle. Wheels
...
Inspection
CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS) > AT OIL TEMP Warning Light DisplayINSPECTIONDIAGNOSIS:• CAN communication is lost with the combination meter.• Combination meter malfunction• TCM is in special control mode.• AT learning is not finished.TROUBLE SYMPTOM:&bul ...