Diagnostic Aids

After engine is started, engine coolant temperature should rise steadily to approximately 194°F (90°C) then stabilize when thermostat opens.

If engine has been allowed to cool to an ambient temperature (overnight), coolant temperature and intake air temperature can be checked with a scan tester and should have similar readings.

Code 14 will set if Gray/Black wire is shorted to ground. If code is intermittent, see TESTS W/O CODES article in this section.

Fig 1: Code 14 - Schematic (All Models) ECT Circuit High/Low Temperature Indicated

Fig 2: Code 14 - Flow Chart (1 Of 2) (All Models) ECT Circuit High/Low Temperature Indicated

Fig 3: Code 14 - Flow Chart (2 Of 2) (All Models) ECT Circuit High/Low Temperature Indicated