2002 jeep grand cherokee code 1281

SOURCE: Trouble code 54 on a 1995 Jeep Grand Cherokee

Carb'ed Engines:
Code 54 - Mixture Control (MC) solenoid is shorted or the ECM is faulty.

Fuel Injected Engines:
Code 54 - Camshaft (or distributor sync.) reference circuit - No camshaft position sensor signal detected during engine rotation.

Hope this helps

Mike

SOURCE: 2002 jeep grande cherokee check engine light

A common problem on many of the new cars is that when a person gets gas, they don't tighten up the gas cap. This will turn on the check engine light. Did you get gas recently? Another option is to see what code is stored in the ECU that turned the light on. This is done with a scanner tool. If you do not have a scanner, then have a dealer look at it.

SOURCE: engine code 95 jeep grand cherokee lerado

12 is a battery disconnect within the last 50 start cycles and 55 means the end of the diagnostic cycle.  Basically the computer found nothing wrong. The 12 code may seem incorrect if you haven't disconnected the battery recently, but from my experience the 12 code shows up almost all the time regardless.

SOURCE: 2002 Jeep Grand Cherokee Lardo misfiring

You say you changed the cam sensor. A1391 code is a crank sensor on the top of the trans. bell housing.

SOURCE: How do you program a 2002 Jeep Grand Cherokee FOB?

if you have an original working fob and your owner's manual,it will explain procedure,otherwise will have to go to dealer to be programmed