FixVault

Diagnostic Aids

After engine is started, engine coolant temperature should rise to approximately 194°F (90°C) and stabilize when thermostat opens. If engine is allowed to cool to ambient temperature, or overnight, coolant and IAT sensor resistance or temperature may be checked with a scan tester. Resistance reading for both components should be the same or close.

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

COOLANT TEMPERATURE SENSOR RESISTANCE

Temperature: °F (°C) Resistance: Ohms
210 (100) 185
160 (70) 450
100 (38) 1800
70 (20) 3400
40 (4) 7500
20 (-7) 13,500
0 (-18) 25,000
-40 (-40) 100,700
Fig 1: Code 14 Schematic, Coolant Temp. Sensor (CTS) Circuit Low Temperature Indicated
G91F16985
Fig 2: Code 14 Flow Chart, Coolant Temp. Sensor (CTS) Circuit Low Temperature Indicated
G91H16987