If improper ECTS(Engine Coolant Temperature Sensor) signal is sent to ECM, it can cause hard starting.
Connect a scantool to Data Link Connector(DLC).
IG "ON"
Select current data function on the scantool.
Check if there is a big difference between the value of "COOLANT TEMP.SENSOR" and that of "INT.AIR TEMP.SNSR".
Specification : At initial starting, the value of coolant temperature sensor is similar to that of intake air temperature sensor.
Is the ECTS data normal?
YES
ECTS is OK.
NO
Go to "Power circuit Inspection" procedure as below.
IG "OFF"
Disconnect ECTS Connector.
IG "ON"
Measure voltage between terminal "1" of the ECTS harness connector and chassis ground.
Probe(+) : Terminal "1" of the ECTS
Probe(-) : Chassis ground
Specification : Approx. 5V
Is the voltage within Specification?
YES
Go to "Ground circuit Inspection" procedure as below.
NO
Faulty ECM
IG "OFF"
Disconnect ECTS connector.
IG "ON"
Measure voltage between terminal "3" of the ECTS harness connector and chassis ground.
Probe(+) : Terminal "3" of the ECTS
Probe(-) : Chassis ground
Specification : Below 0.5V
Is the voltage within Specification?
YES
Faulty ECTS
NO
Check open between ECTS harness connector and ECM harness connector.