I have an 01 Ram 5.2 5 Speed. I have a Hypertech programmer installed and for some reason my truck keeps throwing the P1281 code. I looked in the haynes repair manual and it says that code means that the "Engine is cold too long". I park my truck in heated garage every night and it usually never gets below 50 degrees. It does not throw the code every day but it has done it about 5 times in the last month. I have no idea why its doing this, it has been cold here (PA) but like I said the truck stays in the garage. I dont think its a big deal, it still runs fine and I usually just turn off the CEL with my programmer, it just bothers me. Any info anybody has on this will be appreciated!

 

it has little or nothing to do with the outside air temp. the code is caused by your engine failing to reach a 'warm' temperature within a certain amount of time (~5 minutes). its usually caused by a bad thermostat.

i was getting this 2 weeks ago. t-stat was bad, not warming up. little to no heat. temp gauge would barely climb into the normal range and took 10-15 minutes to get there. replaced t-stat with new 180 and now it comes up to about 1/3 of the gauge within about 5 min.

from service manual.
P1281 Engine is Cold Too Long Engine coolant temperature remains below normal
operating temperatures during vehicle travel (Thermostat).

 

code i get for the P1281 : control fuel air metering

 

I got that code once after installing a new 180* tstat (stock is 195*), but it was because I had my electric fans wired to the A/C switch and they turned on when I needed heat in the winter, and the fans did too good a job cooling the radiator in the cold air. The A/C and heat both come on when you turn on the temp controls; blend door determines whether or not you get hot or cold. I never understood why they did this as the A/C uses more gas on than off and in the winter you could regain some of that lost MPG due to the "winter mix" gas if the A/C compressor would just stay off.

Anyway, +1 to what dhvaughan said, Tstat has failed in the open position (a good thing if a failing tstat can be) and coolant constantly runs through the radiator, being cooled before it needs to be. You'll waste a lot of gas running like this as the engine will run rich (heavy on the gas mix) to try to heat up the block to reach normal operating temp.

 

That all makes good sense, I appreciate the help.
I never really thought about it but the truck does take a long time to get warmed up, I can drive for about 15 minutes before it even registers a temperature.
I guess I had a stupid moment thinking that it may have something to do with my cold air intake, but now that I think about it that wouldnt make much sense...
How hard is it to put in a new T stat? And ive read that alot of brands are $hitty but is there one that is better than the others? Id like to get a 180* one if Im going to do it...

 

Would this tie into the other post where the computer would try to compensate by dumping fuel into the engine to warm it up faster?
I havent checked my mileage lately, Im kinda scared to.... I know I only get about 250 miles to a 26 gallon tank of 93 octane and I know it used to be better than that...

 

you gotta remove the alternator to get to the thermostat. other than that its not a big deal.

 

i recommend stant superstat for about $9-10, your choice of 180 vs 195. i run 180. i would avoid the $5 autozone ones. besure and get a new gasket. the t-stat probably does not include the gasket. clean all surfaces. i put a very light coat of rtv on both sides of gasket. be sure and put spring side down. if you've never done a good flush, this is a good time....

there is a stupid tab on the t-stat neck that says 'front', which, if present, will likely force you to remove the alternator, which is not too bad, but just a few more bolts. if your tab has already been removed, then you can get the neck off w/o removing the alt, but you might want to remove that black top brace for a little more room. if your tab is still there, you should grind if off for next time.

look in the diy at the top of 2nd gen. i think there is a thread on it.

 

I feel like a rookie asking about how to put it in, I have worked on this truck enough I should know whats up with how to put it in....
Anyway, I have a new serpentine belt that i need to put on, ( my current one isnt bad but its starting to get cracks) just preventative maintenence. So that will motivate me to get on the ball with the T stat. Where can I get a superstat?? I want to order one asap so i can do it this weekend....

 

any local auto parts store, except for maybe autozone, i don't know if they carry anything other than their own brands or not.

this site is down at the moment, but several good DIY threads here.
http://www.pavementsucks.com/tech/tstat.php