Check Engine Light - P0128 Thermostat Implausibility

[thecastle]

I was just on a 2400 mile work trip 2 weeks ago. Had a check engine light appear, solid not flashing. Stayed on for about 600 miles figured it was bad diesel as it went away after a refil. Once home ran alpha OBD and we had a stored P0128 code, thermostat implausibility which indicates the coolant temps were too low in the truck. Not sure why the check engine light disappeared, but I think it was 26 F outside on the days it was appearing. I've driven in 15F weather never had a check engine light on previous trips.

Is this a common issue? I can't find any threads on it. Suggestions on what I should check, or just ignore it?

 

[H3LZSN1P3R]

Check the coolant temp screen after running for a while. My 19 i have had to change the t stat already once as it was opening to early i never received a code though as the temps were around 170-175°

 

[thecastle]

Thank you. I noticed my engine was staying around 150-160. I dropped it off at the dreaded ram dealership to replace the thermostat hopefully under powertrain warranty. I've never had a t-stat fail this quickly, is this a common cummins thing?

 

[H3LZSN1P3R]

Thank you. I noticed my engine was staying around 150-160. I dropped it off at the dreaded ram dealership to replace the thermostat hopefully under powertrain warranty. I've never had a t-stat fail this quickly, is this a common cummins thing?

Not usually a common thing but we all know how things are getting built these days…

 

[thecastle]

thanks!

The scumbags at One Star Dodge aka Big Star told me the t-stat needs to be replaced and is not covered under powertrain warranty. They told me it will be $1098 to replace the t-stat. I asked them, "how much are you charging for a t-stat?" Advisor gave me the song and dance and said "well prices have gone up on everything..... But $350." I said, no thanks, I'll take it to an independent or diy the job. (AutoZone charges $31.99 for the t-stat and $850 in labor is high for a t-stat replacement). The service advisor paused and said "let me verify the price, I'll call you back." Magically now the t-stat replacement is covered under warranty and the t-stat replacement is no charge. Its pretty likely that Big Star was always going to charge the warranty for the job, they just wanted to see if they could some free money from me $$$. I sure feel sorry for people who don't know what is under warranty and what things actually cost...... Man I wish I could find an honest, competent ram dealer, it truly is the worst part of the ownership experience. But I still like the truck.

 

[Will_T]

Man I wish I could find an honest, competent ram dealer, it truly is the worst part of the ownership experience.

Sad but in my experience so true. It depends where you are I guess as some have said it has been ok for them. In my case the other two manufacturers' dealers in town are light years better than the Ram dealer. It was something I overlooked when buying. I love the truck but knowing what I know now, I would have taken my chances with another brand just to not have the pain of dealing with Ram dealers. By far they are the weakest link.

 

[H3LZSN1P3R]

thanks!

The scumbags at One Star Dodge aka Big Star told me the t-stat needs to be replaced and is not covered under powertrain warranty. They told me it will be $1098 to replace the t-stat. I asked them, "how much are you charging for a t-stat?" Advisor gave me the song and dance and said "well prices have gone up on everything..... But $350." I said, no thanks, I'll take it to an independent or diy the job. (AutoZone charges $31.99 for the t-stat and $850 in labor is high for a t-stat replacement). The service advisor paused and said "let me verify the price, I'll call you back." Magically now the t-stat replacement is covered under warranty and the t-stat replacement is no charge. Its pretty likely that Big Star was always going to charge the warranty for the job, they just wanted to see if they could some free money from me $$$. I sure feel sorry for people who don't know what is under warranty and what things actually cost...... Man I wish I could find an honest, competent ram dealer, it truly is the worst part of the ownership experience. But I still like the truck.

Thats just criminal those types of dealers you should always report them to FCA and the BBB