Comanche 4WD L6-242 4.0L VIN S MFI (1992)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
Coolant Temperature Sensor Test
PROCEDURE
1. Disconnect wire harness connector from Engine Coolant Temperature (ECT) sensor.
2. Test the resistance of the ECT with a high input impedance (digital) volt-ohmmeter.
^
The resistance should be less than 1000 ohms with the engine warm. For actual resistance values, refer to the following ECT/MAT resistance
chart. Replace the sensor if it is not within the range of resistance specified in the chart.
3. Test continuity of the wire harness. This is done between engine controller wire harness connector (terminal 2) and the sensor connector terminal.
Also check continuity between wire harness (terminal 4) to the sensor connector terminal.
^
Repair the wire harness if an open circuit is indicated.
...............................................................................................................................................................................................................................................
TEMPERATURE
RESISTANCE (OHMS)
°C
°F
MIN
MAX
...............................................................................................................................................................................................................................................
-40
-4O
291,490
381,710
-20
-4
85,850
108,390
-10
14
49,250
61,430
0
32
29,330
35,990
10
50
17,990
21,810
20
68
11,370
13,610
25
77
9,120
10,880
30
86
7,370
8,750
40
104
4,900
5,750
50
122
3,330
3,880
60
14O
2,310
2,670
70
158
1,630
1,870
80
176
1,170
1,340
90
194
860
970
100
212
640
720
