I bought my 03 Ram back in February from the original owner. In the past two weeks I've had the P0602 error code come up and a lamp out come on as well. I have a bully dog power pup installed on the truck and the error code only shows up when it is on. I went on the bully dog site to look it up and i guess the power pup is too old to refer to and find what it is. I know P indicates powertrain but have found nothing. I took of the power pup and used car md cuz it wont run with the power pup on and it comes out clear. As for my lamp out, idk what is wrong. It come on and off. No consistancy except that if i hit a bump it may go on or off. I have checked my lights and lamps and they all work. Are the two connected maybe? Should I worry?

 

P0602

Possible causes
- PCM not programed
- PCM program
- Faulty PCM
- Wrong PCM
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0602 DODGE Description
This diagnostic trouble code (DTC) indicates a programming error within the powertrain control module (PCM).



Read more: OBDII Code P0602 DODGE - Powertrain Control Module Programming Error | Engine-Codes.com

Looks like a possible wiring/connection/ground issue, or a ECM/PCM issue?? Probably something wrong with your programmer...I'd upgrade that if the truck is fine when you don't have the existing one installed.

As for the light issue...I've had bulbs with bad filaments cause the symptoms you describe...pull each bulb, scrutinize the filaments closely, you will likely find one that is broken near the filament holder and is losing contact when you hit a bump.

 

my 04 does the light thing it drives me nuts.. im buyin all led lights for it