SPOUT circuit open and ECT out of range

5.0guy

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Apr 17, 2004
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I ran the KOER test on my 90 5.0 and I got codes 21, 94, 44, and 18. I know that 94 and 44 are due to my smog equipment being removed, but 18 and 21, I don't know too much about. From my understanding, the SPOUT circuit being open means I'm running at base timing. So can I just get a new SPOUT? What's this thing even look like? And about the ECT being out of self-test range...what's that all about? Also, on the KOEO, I got code 13 which says that the ISC did not respond properly. What can I do about that?
 
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The SPOUT connector is on the wiring harnes right up by the distributor. It is a black wiring connector and should have a gray plastic block in it. That is the SPOUT jumper. Check up there and make sure that it is in. If not I would say junkyards or talk to a dealership.

As far as the ect goes I would probably replace it and that should take car of it.
 
Code 21 – ECT sensor out of range. Broken or damaged wiring, bad ECT sensor. Note that that if the outside air temp is below 50 degrees F that the test for the ECT can be in error.

ACT & ECT test data:

The ACT & ECT have the same thermistor, so the table values are the same

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer. Here's the table :

68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms