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Discussion Starter #1
Does anyone know of a diagnostic check for the CTS
 

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She Don't Smoke!
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Diagnostic check? Here is all I got for the CTS or according to this, ECT :p

An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. Disconnect ECT sensor harness connector. Measure resistance between ECT sensor and terminals. Sensor resistance should be as specified. (See resistance values table). Resistance should be high when engine is cold and rop as engine warms. With vehicle sitting overnight, IAT sensor and coolant sensor should have close to the same resistance reading.

ECT Sensor Resistance Values

Temperature in F.........................Ohms
212........................................177
158........................................467
104........................................1459
68..........................................3520
32..........................................9420
5............................................21450
-40.........................................100700
 

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Discussion Starter #3 (Edited)
Diagnostic check? Here is all I got for the CTS or according to this, ECT :p

An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. Disconnect ECT sensor harness connector. Measure resistance between ECT sensor and terminals. Sensor resistance should be as specified. (See resistance values table). Resistance should be high when engine is cold and rop as engine warms. With vehicle sitting overnight, IAT sensor and coolant sensor should have close to the same resistance reading.

ECT Sensor Resistance Values

Temperature in F.........................Ohms
212........................................177
158........................................467
104........................................1459
68..........................................3520
32..........................................9420
5............................................21450
-40.........................................100700
Thank you. That is just the information that I have been looking for. You say that it may not set a trouble code. Does that mean it will never set a code or just sometimes it won't. I do sometimes get a pending code that shows my temps at -40 deg and 0 for speed RPM & load. This happens when I am moving. Do you mean between the sensor terminals?
 

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She Don't Smoke!
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Sorry, I didn't mean for the "and" to be in there lol... yes measure the resistance with your DMM (Digital MultiMeter or w/e you have in your toolbox) between the ECT Sensor Terminals. I knew I should have proofread my info lol... oh well.

The sensor may throw a code or may not. Most of the time it doesn't, but I'm also used to OBDI vehicles so far...
The -40 degree temps make me think that you are getting a bad connection somewhere to the sensor. When you unplug the sensor, and start you truck. The ECM will read -40 degrees and your truck will raise idle slight and advance the timing a bit as well. But back to the sensor, i guess you can start by testing the sensor first, and while you are there, check your connector. IIRC the connectors are known for going bad, mainly wires corroding or breaking off at the connector.
 

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Joe, if you're getting '0' readings for speed,RPM, and load this would indicate multiple sensor failures which almost always leads to bad grounds/connections. Plus it sounds to me like it is intermittent.
 

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She Don't Smoke!
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Joe, if you're getting '0' readings for speed,RPM, and load this would indicate multiple sensor failures which almost always leads to bad grounds/connections. Plus it sounds to me like it is intermittent.
I do agree with you that those problems could be from grounds. I wouldn't think that multiple sensors would fail at the same time... Then again I didn't think I'd be paying almost $2.00 a gallon for diesel again, but it's been close :D

But like I said, some of the connectors are 100% weatherproof i guess you could say as they do fail sometimes... Or the connectors may not be all the way on, On my truck, the ECT sensor connector is very sensitive... Every once in a while if i would bump it and go driving afterwards my torqueconverter would unlock on the highway and i have to push down and wiggle my connector and i'm on my way until i bump it next time....

sorry if i'm rambling or not making sense... I'm really bored and tired... not a good combo for giving advice i guess lol!
 

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Discussion Starter #7
Joe, if you're getting '0' readings for speed,RPM, and load this would indicate multiple sensor failures which almost always leads to bad grounds/connections. Plus it sounds to me like it is intermittent.
It is intermittent & where should I start looking for grounds for this circuit?
 

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check engine bay grounds, i think one is on the back of one of the heads...i'm tired and hung over so my memory is lacking right now
 

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Discussion Starter #10
check engine bay grounds, i think one is on the back of one of the heads...i'm tired and hung over so my memory is lacking right now
Happy hangover;):D
 
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