ECT readings vs. gauge temp readings after tune

[ryans_ws6]

Hey guys,
I recently tuned my buddies 2015 lml truck. And now we are getting a p01f0. So I hooked the scan tool to it and the ECT sensor is reading 155* when the gauge cluster is displaying 185*. All I read about is p01f0 is caused by a stuck thermostat. But this all came after I installed a tune. Trying to figure out if it was just coincidence or do I have a tuning issue.

 

[kidturbo]

Not sure on the LML, but the LMM has two ECT sensors in the thermostat hosing. If same, I'd suggest unplugging them one at a time to identify which values are linked to each reading. Possible the scan tool is reading one sensor, while dash is reading the other. Best guess off top of my head, is unlikely any tune work modified the ECT readings.

 

[Harbin_22]

Not sure on the LML, but the LMM has two ECT sensors in the thermostat hosing. If same, I'd suggest unplugging them one at a time to identify which values are linked to each reading. Possible the scan tool is reading one sensor, while dash is reading the other. Best guess off top of my head, is unlikely any tune work modified the ECT readings.

So you know, only the early LMM had two sensors. Not sure when the changeover was, but my 2010 only has one

 

[Yngdmax92]

Return it back to stock and see if the problem is still there

 

[kidturbo]

So you know, only the early LMM had two sensors. Not sure when the changeover was, but my 2010 only has one

Thanks for that info I'll check for pinout diff on a 10.

I've verifved the ECM only ever uses one for calculations, but both can be read with a scan tool. Reason I guess that was his issue. My GM buddy told me the reason for second sensor, but it's been so long ago I forgot their reasoning ..