My son has a 2002 Dodge 2500 Diesel has codes P0522 and P0336.  The oil pressure switch, which is a single wire switch, has been replaced with a Cummins part and the PO336 code is troubling because there is no crank shaft sensor on a 2002.  When you start the truck the instrument cluster shows no oil pressure and the tach is erratic for 8 seconds then drops off and the truck runs at a normal RPM but is in limp mode.  ANY help would be appreciated.

We always say start with codes, which you did, then go through all grounds. Do a WT mod it helps a lot of things. To me it sounds like a bad connection, before you get all crazy with ECM, pcm, cluster, etc, I would make sure your wiring and batterys are in good shape, maybe check alternator for AC noise.  

On 4/19/2020 at 4:10 PM, jamesroessler said:

the PO336 code is troubling because there is no crank shaft sensor on a 2002.

 

Yes there is... It's the cam sensor on the 2002 Dodge. The early series had the crank sensor at the crank. Now ther relocated the crank to the cam and the cam sensor was ditched. I just changed my landlords cam sensor. All you need is a allen wrench and patience. Even with my big hands I got in there pulled it out and replaced in about 30 minutes. He had the same problem.

I replaced the cam sensor with Cummins part and still has this issue. Ohmed the bus wires from ecm to pcm and they are good. Oil pressure switch is single wire going to ecm with 4.9 volts but the code shows oil pressure switch low voltage?  Could this be an ecm issue?

31 minutes ago, jamesroessler said:

I replaced the cam sensor with Cummins part and still has this issue. Ohmed the bus wires from ecm to pcm and they are good. Oil pressure switch is single wire going to ecm with 4.9 volts but the code shows oil pressure switch low voltage?  Could this be an ecm issue?

You sure the oil pressure switch has voltage on it. It is not on the 5v system as far as I can tell. The 3 wire pressure senders are part of it, orange wire carries the 5v. Even the 02 wiring diagrams dont show the single wire switch.

Yes definitely single wire. A friend of ours has the exact same year and his is single wire also. We put our pcm on his and it works perfect so that’s why I’m guessing Ecm??

Block is the ground for that sensor. So the 5V comes off the ECM the oil pressure sensor is single wire just like back in 1970s when V8 engines had a single wire oil pressure sensor.