Code p1391 showed up on the code reader when it was hooked up, chech engine light is on?

Both point to a problem with a module rather than a sensor. We have an auto-electrician Expert here and hopefully he will be along. The first thing to do is clear the codes and see if they come back. If they do, you need a good auto-electrician, not a mechanic and not a guy from Autozone.

This tells you what causes P1698.

P1698 JEEP Code - PCM Fault No CCD Message From TCM

https://www.engine-codes.com > p1698_jeep
'P1698 JEEP code possible causes · Faulty Transmission Control Module (TCM) · Transmission Control Module harness is open or shorted · Transmission Control Module ...

This tell you all the items that can cause P1391.

P1391 JEEP Code - CMP or CKP Signal Intermittent Condition

https://www.autocodes.com > p1391_jeep
'P1391 JEEP code description ... The Powertrain Control Module (PCM) monitors the Camshaft Position Sensor (CMP) Or Crankshaft Position Sensor

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Does the code reader power up ? Does a message no communication show on the screen ? Is there B+ voltage at pin 16 in the DLC ? If all that is good try a auto parts store ,they check codes for free .

That code is indicating an intermittant crank shaft or cam shaft sensor fault. Because the engine is starting then stalling, check to see if you have spark after the stall. If spark is still present, you are probobley looking at a cam sensor circuit issue. The cam sensor controls the fuel injector pulse. If the cam sensor fails on a chrysler product, the fuel injectors will not function.

The service engine light should only come on when the PCM detects a fault in one or more of the systems it controls. It should also store codes.
If a simple code reader was hooked up to read the codes perhaps the code reader is only good for the generic codes and your PCM has model specific codes stored in it. Some code readers cannot read those codes. A shop scanner may be needed to get codes.

Take it to advanced auto and let them hook their OBD2 reader up to it and find out what it says, or take it to a machanic and pas over $60.00

check engine light and code P1391 crank or cam position sensor

The above can cause rough idle on the Dodge Ram 1500 5.2L V8 Engine.

Can try to replace the sensor, but verify that the wires are ok first.

chech the cigatette lighter fuse

glow plugs preheat the fuel to help the engine start.....when its hot outside its not that bad...the colder it gets the harder it will be to start with bad glowplugs..

crank sensor probably cracked heat expand the crack and vehicle stahls

P1391 Intermittent Loss Of CMP Or CKP Sensor Signals - From engine-light-help,com
I believe it to be a Crankshaft Position Sensor.