Pro-Link compatibility?

[Iceni John]

After my first Pro-Link scanner was stolen I bought another Pro-Link off eBay, but it has a problem I never had with the first scanner.   The new software cartridge is for DDEC II and III (series 5.2), compared to the original one that was for DDEC I and II  -  my engine is DDEC II, made in March 1990.   This new cartridge was supposedly new and unused, still wrapped in its plastic and with an unopened manual  -  I know this doesn't prove it's unused, but it looked pristine, with no wear marks on its contacts from being slid into the base unit.

The problem very simply is that it won't talk to the ECM.   It just does not recognize it at all.   I checked continuity of all the wires from the ECM's 30-pin connector to the under-dash diagnostic port  - all's OK.   The ECM flashes out codes on the CEL without a problem (I only have code 25 now  ), proving that the wiring is OK  -  no difference.    I used the optional 12V power cable to power the Pro-Link, even though it's not needed for DDEC  - no difference.   I even bought another base unit and some more cables, thinking that they could have been at fault  -  no difference.

It looks like that series 5.2 cartridges don't like my ECM.   I vaguely remember someone here some years ago saying something about DDEC II coming in two different versions;  maybe the 5.2 cartridge is for a different generation of DDEC II?   Is there another version of DDEC II and III cartridge that will work with my engine, or do I have to use another DDEC I and II cartridge like before.   At this time all the cartridges on eBay are much too expensive, but it looks like I will need to buy another one.   Does it need to be earlier than 5.2, or later, or what?

Thanks, John

[Bill Gerrie]

John
Just an idea but read page 12 in the manual that came with the cartridge. Inside there is a 2 amp fuse. Maybe it is blown. 

[Iceni John]

Bill, I took the cover plate off the cartridge this evening and tested the fuse  -  it's OK.   So, methinks it's a compatibility issue here.   Has anyone else here with a 1990 DDEC II had a similar problem with a 5.2 cartridge?

John

[luvrbus]

In section 4 of the manual it tells you how to jump and check the data link have you tried that,try it on another DDEC 11 if you can find one to be sure the prolink is not bad.I don't have any DDEC 11 cartridge's any longer or I would send one to you 

[Iceni John]

In section 4 of the manual it tells you how to jump and check the data link have you tried that,try it on another DDEC 11 if you can find one to be sure the prolink is not bad.I don't have any DDEC 11 cartridge's any longer or I would send one to you 

I can flash out codes on the CEL without a problem, so I'm thinking the data link between ECM and diagnostic port is probably OK.   All the five wires (and the separate ground) continuity also tested well with negligible resistance.   I'll read the manual again tomorrow about the data link.

Maybe tomorrow I can ask ABC Bus if they still have a DDEC II Pro-Link that I can test, but I suspect they don't still have one.   I want to either test my cartridge on a DDEC III, or borrow another cartridge to test my DDEC II.

I actually have a spare DDEC II ECM from another bus like mine, but I would need to make an adapter to plug my Pro-Link to it.   It came with its 30-pin plugs still in it, so I would need to solder wires to the five pins that connect to the diagnostic port, then get another Packard/GM 12-pin port for the other end  -  not fun!

John

[luvrbus]

Yours being a 1990 would make it a early DDEC ll ,they changed suppliers about the middle of the run in late 1991 going to Motorola   

[Bill Gerrie]

I use a DDEC II III cartridge on my DDEC IV as a test unit while traveling. It is plugged in at the dash just to read the temp etc. I have used the same 5.2 cartridge on my friends 1998 Prevost with DDEC II and no issues. I did not realize the mfg of the ECM was changed in mid run so I haven't used it on an older unit. Cliff should know as he is very knowledgeable about these things.   

[Gerry H]

 I'm using that same version (5.2 DDC11) on my 92 with no issues. Gerry H

[Iceni John]

I'm using that same version (5.2 DDC11) on my 92 with no issues. Gerry H

In which case you probably have a Motorola-made ECM, and mine's probably not a Motorola.   Why that should make a difference to the Pro-Link software, who knows, but I've got nothing else to go on at this time.   I guess a pre-5.2 software cartridge, or a DDEC I/II cartridge like I had before, is the only answer for me.   Hrumph.

John

[luvrbus]

The early DDEC are in a different world ,you could just remove the DDEC on the early l and ll's models and change to a mechanical setup when they changed over you had to replace the cams in the later DDEC 11 to make one run BTDT scratching my head for a week