ECT sensor

[chrisk1500]

The ECT (engine coolant temperature) sensor is located in the coolant crossover tube. It has a weatherpack connector running to it with two wires (yellow and black).

The truck's computer uses the information from the ECT to adjust a number of things. It determines timing advance, OD engagement, fuel delivery, and glow time. Unplugging the ECT is a diagnostic aid used to check the glow system. This is because when the ECT sensor is unplugged the computer thinks the engine is -40* F.

Here is a table of resistance values and temperatures you can use to check your ECT.

177 ohms @ 212 deg. F. or 100 deg. C.
241 ohms @ 194 deg. F. or 90 deg. C.
332 ohms @ 176 deg. F. or 80 deg. C.
467 ohms @ 158 deg. F. or 70 deg. C.
667 ohms @ 140 deg. F. or 60 deg. C.
973 ohms @ 122 deg. F. or 50 deg. C.
1188 ohms @ 113 deg. F. or45 deg. C.
1459 ohms @ 104 deg. F. or 40 deg. C.
1802 ohms @ 95 deg. F. or 35 deg. C.
2238 ohms @ 86 deg. F. or 30 deg. C.
2796 ohms @ 77 deg. F. or 25 deg. C.
3520 ohms @ 68 deg. F. or 20 deg. C.
4450 ohms @ 59 deg. F. or 15 deg. C.
5670 ohms @ 50 deg. F. or 10 deg. C.
7280 ohms @ 41 deg. F. or 5 deg. C.
9420 ohms @ 32 deg. F. or 0 deg. C.
12300 ohms @ 23 deg. F. or -5 deg. C.
16180 ohms @ 14 deg. F. or -10 deg. C.
21450 ohms @ 5 deg. F. or -15 deg. C.
28680 ohms @ -4 deg. F. or -20 deg. C.
52700 ohms @ -22 deg. F. or -30 deg. C.
100700 ohms @ -40 deg. F. or - 40 deg. C

 

[Turbine Doc]

Hey I'm thinking once we get it all together a new & better Phoenix will arise from ashes.

Looks good Chris

 

[RadioMan]

Thanks! Just printed the values for tomorrow.
My ECT is not only disconnected, but the plug has been cut off

The bucket truck has remote start and stop from the bucket. I wonder if the remote start is the reason ECT being disconnected :confused5:
The lift pump also runs all the time, I don't think that this is a good thing. Probably also for the remote start to work (?). I haven't found how the LP is being kept running yet - could be the OPS is stuck -- or it was done intentionally.

Seems to me that once the engine cranks a bit the OPS will turn the LP on anyway, so it doesn't need to be on all the time. Correct??

 

[preachermic]

Thanks Chris I will check it tomorrow morning. My ECS sensor is about 2 years old and my truck starts very rough unless I set the switch to where the ECS sensor is bypassed . Other than that my truck runs perfect.

 

[preachermic]

I'm getting 3.1 ohms. I'm guessing that the sensor is dead.

 

[JiFaire]

I'm getting 3.1 ohms. I'm guessing that the sensor is dead.

Yep - that's pretty much a dead short. Your glow plugs will be at the minimum cycle, so you may have some cold-start issues as a result.