2001 2500 2wd auto cummins. Out of the blue while everything seems to be OK. Temp 180 checked by laser heat gun. The check gauges light comes on and temp gauge goes to 240 in about 10 seconds.  Turn it off and back on temp slowly raises to 240. This happened as soon as I started it and engine is cold. Last week the ck engine emoji came on and water in fuel. I drained the filter and saw no water. ???? Bad ground?? anybody seen this happen?

Check error codes and list the numbers out... There might be more at hand here. 

5 hours ago, Mopar1973Man said:

Check error codes and list the numbers out... There might be more at hand here. 

You answered this question previously and I found in on the cummins forum. You supplied a wiring diagram and said I probable had a code P- 0118. Very helpful to have a schematic. What should I find at pin 11 from the ecm? Full continuity? I have 3 years experience in auto elect but it was 1966-69. I will do some checking and get back to you with results. ALSO,, goes to 240 with sensor unplugged.

Edited August 15, 20195 yr by oldbeek
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Pin #11 of the ECM is the common sensor ground for: the water in fuel sensor, engine coolant temperature sensor, intake air temperature sensor, and engine oil pressure sensor.  There is a common splice point in the harness for this black with light blue tracer wire.   When ohm testing between the #11 pin and the sensors the reading should show continuity with low resistance.   I think @dripley has had problems with that splice. 

Problem righted its self this morning after a few starts and stops. I will ck the ohms on that ground wire while it is being correct. Thanks for the answers.

On 8/15/2019 at 4:48 PM, IBMobile said:

Pin #11 of the ECM is the common sensor ground for: the water in fuel sensor, engine coolant temperature sensor, intake air temperature sensor, and engine oil pressure sensor.  There is a common splice point in the harness for this black with light blue tracer wire.   When ohm testing between the #11 pin and the sensors the reading should show continuity with low resistance.   I think @dripley has had problems with that splice. 

I thought I did until I found the problem to be in the 5v where I had to splice it many years ago. 

21 hours ago, oldbeek said:

Problem righted its self this morning after a few starts and stops. I will ck the ohms on that ground wire while it is being correct. Thanks for the answers.

I fought the same issue for several weeks. My exhaust brake connects to the ECT sensor. I hunch I took it loose and it stopped. Figuring something in that wiring harness is bad.