Hey guys, been awhile.

My truck (2001 Dodge Ram Quad Cab 1500, 4x4, 5.9 gas motor, 46RE trans) has been throwing the P1281 code. I know it indicates "engine cold for too long". Problem is it only throws the code after the temp gauge is half way between 130 & 210. P1281 should be "engine not warm enough (170*) in 20 minutes" according to my service manual.

This started giving the code in the past 2 months. In May, I moved the truck & shop equipment to Kansas from Arizona. It got hot in one spot, about 230-240 degrees. That hot spot lasted maybe 10 minutes, kept the truck running with the electric fans running until it cooled down to below 200. That took maybe another 20 minutes. Trans got hot (idiot light) & my converter is bad now.

It's much cooler here in Kansas than in AZ, but the truck should still warm up. I've put 2 different thermostats in rated at 192*. First one was a fail safe, but it still worked ok. Replaced it anyway. After the second non-fail safe 192* thermostat installed the code returned. Truck has 163K on the ticker, so figured it was the sending unit. Swapped for an Echlin from NAPA (I've had good luck with Echlin products).

After the temp sensor swap, engine warmed up within 15 minutes to 190*, electric fans kicked on at 200*, cooled the motor down to around 180ish electric fans cycled off. They would do this as the truck was fully warmed up & running in the driveway idling. Truck has enough coolant in it, proper mix (I checked -40* mix) ran the heater on full hot while it was warmed up & could hear air moving through the heater core.

Go to work today, temp comes off the 130* peg within 5 minutes. Temp climbs to approximately 180* & stops. No code, which I'm thinking is a great thing.

Coming home from work today, much warmer, temp closer to 190* all the way home. Travel is approximately 9 miles one way to/from work.

One mile from home idiot MIL light comes on, WITH THE TRUCK FULLY WARMED UP!!!!

I need some help. When I put my electric fans in, I installed a 180* thermostat, it set the P1281 code within 5 miles & the temp gauge never climbed much over the 130* mark. Changed to a 192* thermostat & the problem went away. That was in Arizona.

Here in Kansas, it's a bit cooler, but the thermostat should allow the temp to climb up fairly quick. Do I change to another thermostat? Try the Stant Superstat? Go to a 195* thermostat? Or take it to the dealer & have the computer flashed/drivers updated or some such expensive stuff.

Lastly the truck has a Jet chipset, AirRaid cold air intake, high flow cat & Flowmaster exhaust.

I just don't think the thermostat is bad for the second time. It's a non-fail safe thermostat.

 

Install a stant super-stat. 195 degree. See if that doesn't solve the issue.

I don't like the fail-safe stats, as they fail all to easily.

 

Get some Power Service Diesel 911 and pour that in your tank and fuel filter. You're gelled up more than likely. I don't care what others say, you should be adding an anti gel additive in the winter, like Power Service Diesel Kleen white bottle at every fill up. It's anti gel plus cetane boost and lubes your fuel system.

Oops wrong thread, not sure how I managed that! Mods can you delete this lol