OBD 2 protocol change?

[DLeno]

Hi,



trying to hook up Alex Peper's obd-2 device without success. Any chance the new 2004s are not "ISO"? my "ISO" connector works just fine with my Acura but no can do with the RAM 3500.

 

[rbattelle]

Hmmm... interesting. The OBDII protocol definetly has not changed, but maybe Dodge has changed from ISO. If you look in the end of the connector and tell me which slots have pins, I can tell you which standard it is...

 

[crabjoe]

It seems there are more then one protocol for OBD2. My Auturra scan tool says it's compatible will all OBD2 protocols J1850 VPW, J1850 PWM, ISO 9141-2, ISO 14230-4, and Keyword Protocol (KWP) 2000.

 

[rbattelle]

I have Alex Pepers Tricom connector, and have used it successfully so far on 3 different makes/models including my truck.

 

[DLeno]

Originally posted by rbattelle

Hmmm... interesting. The OBDII protocol definetly has not changed, but maybe Dodge has changed from ISO. If you look in the end of the connector and tell me which slots have pins, I can tell you which standard it is...

2,4,5,7,

9,12,15,16

 

[rbattelle]

It is still ISO. Check your cabling. My source is the SAE J1962 standard (revised April 2002). Page 14 provides the general contact allocations:

1. Discretionary
   
2. Bus Positive line of SAE J1850
   
3. Discretionary
   
4. Chassis Ground
   
5. Signal Ground
   
6. CAN_H line of ISO 15765-4
   
7. K line of ISO 9141-2 and ISO 14230-4
   
8. Discretionary
   
9. Discretionary
   
10. Bus negative line of SAE J1850
    
11. Discretionary
    
12. Discretionary
    
13. Discretionary
    
14. CAN_L line of ISO 15765-4
    
15. L line of ISO 9141-2 and ISO 14230-4
    
16. Permanent positive voltage
    
    [/list=1]
    
    
    
    I'd check your equipment, first.

 

[DLeno]

Boy this is getting interesting. A guy over on the DTR tells me that CANBUs replaced OBD-2 and that the obd scanner mfgs all have to come out with updates before they will work. But he also said that this CANBus came around for the 03 model year and we know that std ISO obd-2 works on the 03s. And my 02 had a CANBus unrelated to obd, so I haven't sorted all this out yet.



You're telling me that the pin wiring of my connector is consistent with OBD "ISO" and suspect a wiring or cable problem.



my "ISO" cable from Alex works just fine on my 97 acura and does not work on my 04 RAM. To my knowledge, however, the OBD port on the RAM has never been tested. so maybe it is bad. I suppose there is a chance that the OBD was DOA on this truck? possible but not likely. I even took the connector out of its metal bracket to see if the ISO cable would make any better connection with the pins. no such luck.



Tell me about the difference between the single "ISO" and the Tricom hardware when used on an 'ISO' obd port. Does he use some intellegent interface switching and auto-detect? I'm wondering if perhaps I should have gotten the tricom instead of the single ISO

 

[Firewalker]

Under the gateway screen / protocol screen, make these setting cahnges

timeouts = 15

protocol check mark iso and gm



on the interfase screen make shure your interface is correctley set.



sometimes you will get an istance connection and sometimes it will take two or three trys that is why you need to change the time outs to 15



Note that the software will connect to our truck under eather protocol iso or the gm one.



click on the data tab

select the line labeled all data

hit the send button.

(the all data function asks the truck to report all possible data info th the obd2 software. )



end the connection, save the specs, then click on favorites and save it there

thenclick on options

then click home page

then select auto connect

then select run favorite

then click ok

then save again under the first saved name



by doing all of this all you have to do in the future is plug in to truck and then fire off software and it will auto connect to your truck with all of the saved settings.



good luck

and if this does not help, call alex and he will walk you through the setup.

ken

 

[rbattelle]

Definetly try what Firewalker said, and let us know if it works.



As for the CAN bus, it's my understanding that it's the communications protocol for the vehicle network, and has little or nothing to do with OBD-II. Remember that OBD-II is mandated by law, so they can't just change communications protocols and get away with it.

 

[DLeno]

yea thats what I thought too, and consistent with my 02 -- CANBus was what you plugged fueling boxes into .



Anyway, I tried Firewalkers plan but still no success. hmmm I wonder if the obd port itself might be bad. need to get the dealer to hook up and verifiy that its live.

 

[Firewalker]

have you connected to any car or truck yet????



Might be a setting on the laptop???? Are you using a null modem cabel going to your router box???



Which obd-2 adapter did you buy????



Do you have the correct com port selected????



are you using a USB adapter???



ken

 

[rbattelle]

Would the dealer charge you to just plug in an OBD-II device and verify that the connector is okay?

 

[Firewalker]

Go to your local autozone auto parts store or another store, most will plug in for free!!! At autzone does!!

ken

 

[rbattelle]

Originally posted by Firewalker

Go to your local autozone auto parts store or another store, most will plug in for free!!! At autzone does!!

ken

Good idea. Let us know...

 

[DLeno]

been to autozone and they wouldn't do it unless I had an engine code. maybe I'll try a different store!



I have succesfully connected to the Acura mentioned before with the same cable, software, and laptop. I'm using the single "ISO" gateway.



I might try the dealer -- a request for service that the OBD port is not active .

 

[rbattelle]

BTW, the Tricom connector does have some sort of logic circuit in it that automatically detects the correct communications settings.

 

[Marco]

VPWM

All,



They've changed the protocol.

It's no longer the ISO 9141 it's now the Variable Pulse With Modulation protocol. Same as GM.



That means that unless you have the adapter that supports multiple protocols you will not get any MSG's.



Hope this helps.



Marco

 

[DLeno]

wow, thanks! no wonder my "ISO" connector won't work! seems I need the tricom

 

[Firewalker]

Now my question is the iso change for 2004????



I do know that my 2003 connects iso or gm.

 

[DLeno]

marco?