01 jeep grand cherokee

P1281 JEEP - Engine Is Cold Too Long...Possible causes; Engine coolant level too low, Faulty thermostat...Start by checking the coolant level, add coolant if level is too low. If the problem persist the thermostat may be faulty. Using the incorrect thermostat or coolant mixture could trigger the P1281 code...Description, Engine Coolant Temperature (ECT) is monitored with engine running. The P1281 code will set if the engine coolant temperature does not reach 181 F (83 C) while driving for more than 3 minutes and less than one hour depending on the engine load and start up temperature.

I have a Grand Cherokee 2002 that I am shaking the engine and low torque when I am on the road and use the brake to ease the speed. There is no visible code on the screen. Can you help me detect the problem?

Weak Alternator causing Low Battery Voltage or short trips (Incomplete charging), may affect P1281 and misfiring too. I have had a random misfires for so long that I just clear the codes from time to time. I might not see them for weeks or month at a time, sometime every day or so. Serendipitously, I was going to be away from my jeep for a week and put it on a NOCO 1 amp Minder/Desulfator/Charger. When I got back, I cleared the codes and found P1281 which was new. After charging, no new codes have popped up. So, I started plugging it in every day and my intermittent start up fast idle went away. My temp gauge was not randomly reading low (which was a recent development fitting code P1291) Misfires never seemed to be cylinders that shared a coil (last time it was 1,4 and 6) Over the years, I had already changed the plugs twice (once back to the factory recommended plug), checked the injector circuits, replaced the injectors. Just before last inspection, I Changed the fuel filter/regulator (which magically cleared the codes by itself immediately!) Replaced the Cam sensor (I had a code at the time, my first one several years ago) It is an I6 and has always seemed rough to me. I chalked it up to being and I6, LOL. But my wife felt the difference with the new Filter/Regulator! It has only been 10 days of keeping the battery topped off, but with the temp gauge behaving I am cautiously optimistic. I have read that code P1291 does not always show up under these conditions, So we will see. I know from experience that my 1998 Ram 360 would not idle after it needed a jump until it ran a while with a foot on the gas. My 1998 ZJ 318 is the same. I chalked it up to the voltage being too low to fire the ignition. But I figured once it was running there would be no problem and in those V8 vehicles I never got a misfire or P1281 code. When I would get Misfire codes in my I6 2000 WJ, it always seemed to be right around when it would be going into closed loop, sometimes going in to limp mode just as I was trying to get on the freeway, that was always fun. So IF it comes down to short trip incomplete battery recharge I will be happy, but sad that it hadn't occurred to me sooner.