'01 OBD port...

[GTrent]

'01 OBD port...wiring

Does anyone have a pic of the contacts in it? Or can definitely verify that the wiring diagram on page 8W-18-3 of the 2001 Ram Truck service manual, volume 1 - is correct?



What I'm dealing with is a conversion that never had the OBD connector (Dodge calls it the DLC - Data Link Connector) wired in. The truck only uses the ECM, so that's all I really want to scan. There's no PCM in it, but I'm having a helluva time with this. Keep getting "Data Link Error" on the reader.



Do the PCM pins (#14) need to be terminated? Or free? None of the code readers I've seen seem to want to deal with the CCD bus either - so can I just ignore pins 3 and 11?



Pin 5 is a ground, so is pin 4 - but none of the OBD protocols I've seen need pin 4 grounded, or for that matter, do anything with it at all.



The reason I'm going through all this is due to the good old dead pedal/smoke issues. I'm thinking IP, but since there's this handy dandy diagnostic system, I'd like to access it to see what the system itself is throwing out regarding DTC's.



From what I see, this year of truck doesn't support CAN protocol, but does support ISO/KWP protocols. Or did I screw this up too?

 

[boaterdan]

GTrent,



Here is what worked for me. I think the 14 pin connector coming right off of the engine is called the C126 connector. I went to a junkyard & picked up a couple old ODB II connectors. I was surprised to find out not all the pin slots in the ODB II connectors had connectors in them. I had to change one of them & add a connector on the pin I needed (special tool). I was able to run a couple 24v engines sitting on stands outside the vehicle so I only had ECMs and the engine harness, no PCMs. I hooked up direct to the engine harness. I read codes from them using EASE Diagnostic software. Doug Alm suggested EASE and it works pretty well. Probably would have worked with most software.



Please look at your wiring diagrams to see if this makes sense for you, in case I have a typo or other mistake…keep in mine, no warranties express or implied…. . but this is what I had hand scratched in my notes from when I did it….



ECM pin C126 pin ODB pin

38 5 7

39 4 6

41 6 3

40 7 11



The EASE connector had 12vdc power & ground so I didn’t need any other connections. If you don’t have external 12vdc you will have to add the following.



ODB



Pin 4 Ground

Pin 5 Ground

Pin 16 12vdc+



Good luck, I hope that helps.



Boaterdan

 

[boaterdan]

GTrent,



Just looked at my post & the columns didn't line up how I expected them. In case you are wondering the first column is the ECM pin out, the second column is the C126 pin out, & the last column is the OBD II pin out.



Boaterdan

 

[GTrent]

Hiya Boaterdan, yep, that helps out. I'll configure the pinouts for the OBD port according to your diagram and take it from there.

Thanks!