DTC P0118: Engine Coolant Temperature Circuit High Input

CIRCUIT OPERATION
• 5-volt voltage is applied to the engine coolant temperature sensor output terminal (terminal No. 1) from the ECM (terminal No. 83) <M/T> or PCM (terminal No. 44) <A/T> via the resistor in the ECM <M/T> or PCM <A/T>. The ground terminal (terminal No. 2) is grounded with ECM (terminal No. 92) <M/T> or (terminal No. 57) <A/T>.
• The engine coolant temperature sensor is a negative temperature coefficient type of resistor. It has the characteristic that when the engine coolant temperature rises the resistor decreases.
• The engine coolant temperature sensor output voltage increases when the resistor increases and decreases when the resistor decreases.
TECHNICAL DESCRIPTION
• The engine coolant temperature sensor converts the engine coolant temperature to a voltage and output it.
• The ECM <M/T> or PCM <A/T> checks whether this voltage is within a specified range.
DESCRIPTIONS OF MONITOR METHODS
• An open circuit is detected while monitoring the engine coolant temperature sensor output.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
• Not applicable

Sensor (The sensor below is determined to be normal)
• Not applicable
DTC SET CONDITIONS Logic Flow Chart


Check Condition
2 seconds or more have passed since the staring sequence was completed.

Judgement Criterion
• Engine coolant temperature sensor output voltage has continued to be 4.6 volts or higher [corresponding to a coolant temperature of -45°C (-49°F) or lower] for 2 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 19 .
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
• Engine coolant temperature sensor failed.
• Open or shorted engine coolant temperature sensor circuit, or connector damage.
• ECM failed. <M/T>
• PCM failed. <A/T>