Codes P1296 and P1687 for Jeep Grand Cher. LTM V8 4.7. codes not on OBD11 list. Ray

Question

Codes P1296 and P1687 for Jeep Grand Cher. LTM V8 4.7. these codes are not on OBD11 list and can't identify them. Vehicle w/ rough idle from normal RPM 1600 + 300 to 400 rpm above normal on idle, goes up & down like a seesaw after a while it turns off. other codes coming up are P0505, P0123, P0138.

Answer 1

P1296 No 5-vollts to MAP sesnor (reference voltage)

P1687 No cluster bus message

P0505 Idle air control motor circuit

P0123 Throttle position sensor voltage too high

P0138 - 02 sensor bank 1 sensor 2 voltage too high

P1296 is your major concern without this 5 volt refernce you have no MAP sensor at all,this explains  why the idle is so high,when you get codes that state voltage high look for harness disconnection