Check engine light,, code 15

[STAGEUP]

Hey guys, so its gotten warmer out lately, and well of course the engine runs a tad hotter. Anyway, the engine light came on today. Truck runs great, just has this light on. Now I know that code 15 is for a coolant sensor, but which one? The ecm coolant sensor, or the gauge coolant sensor? My gauge reads fine BTW. Also, the coolant sensor on the intake manifold is the sensor for the ecm right? Thanks for any input.

 

[The Bronze]

Re: Check engine light,, code 15

Yep, code 15 is for the ECM sensor. Pretty much an "open circuit" code, since an open sensor or lack of ground will cause it. I believe the ground is shared with the MAP sensor, so if it is running okay and no codes, then I would check for 5 volts at the yellow wire (connector pulled off sensor). If you can see the scan tool, when you ground the yellow wire, you could ground the yellow wire and watch the coolant temperature rise over 230 degrees. Easy way out is to stuff a sensor in there since they are so cheap, but you never know where the problem really lies and it sure doesn't help the diagnostic skills.

 

[STAGEUP]

Re: Check engine light,, code 15

Thank you Bronze! I'll check the wires on both sensors just to be sure. So its the sensor on the manifold that reads to the ecm right? Thanks

 

[Quickstop [UK]]

Re: Check engine light,, code 15

The ECM sensor is the one next to the radiator hose on the lower intake.

 

[bezerk]

Re: Check engine light,, code 15

The ECM sensor is the one next to the radiator hose on the lower intake.

-180 degrees