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Cat 9 pin diag port pin layout

Jrod25

Well-Known Member
Joined
Feb 14, 2025
Messages
51
Location
Texas
Yes, the problem I have is it I can't really tell which is the fake and which is the real deal
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,661
Location
G..G..G..Granville.........!! Fetch your cloth.
Yes, the problem I have is it I can't really tell which is the fake and which is the real deal
It's relatively easy. when searching:-

1. Only search for used items.
2. Discard anything that says it is supplied/ships from India, even if the ad says it is "used". I can guarantee it won't be.
3. Discard anything that does not show a carrying case in the photos of the item. An OEM Comm Adapter was ALWAYS supplied in a carrying case when it was new.
4. Look closely at the carrying case. Consider the case style, that it carries the Cat Part Number label, and look for it to be well worn.

See this LINK as an example. I found that in less than 2 minutes. From the photos I would say it is a used genuine OEM Comm Adapter. It's a Series II Comm Adpater so not the latest.

It may be necessary to look for a couple of weeks waiting for one to turn up.
 

Jrod25

Well-Known Member
Joined
Feb 14, 2025
Messages
51
Location
Texas
Ok thanks, I think I'm going to buy one of these, so for my 2013 272D XHP, it doesn't matter if it's an adapter II? I thought I needed adapter 3 but I really do not know what I need apparently. I only need it for my 272d, I would not be using on other equipment
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
38,661
Location
G..G..G..Granville.........!! Fetch your cloth.
The Comm Adapter 3 was introduced on the market around 2012-13, around the time your machine was built. That being the case a Series 2 adapter should work OK, but I suggest that you need to confirm that information before purchasing one. Either that or keep searching, a Comm Adapter 3 will pop up for sale sooner or later.
 

JTWAT

Well-Known Member
Joined
Mar 14, 2012
Messages
233
Location
Central FLA
The Comm Adapter 3 was introduced on the market around 2012-13, around the time your machine was built. That being the case a Series 2 adapter should work OK, but I suggest that you need to confirm that information before purchasing one. Either that or keep searching, a Comm Adapter 3 will pop up for sale sooner or later.
I have purchased 5 "aftermarket" adapters and sent them back in an attempt to connect to my truck with CAT engine. I have also purchased an "on road" cable for it but have not been able to get the adapter to power on. I tested the plug for power and ground and have both where they should be. The only thing I can't determine is which is power and ground on the end of the cable where it plugs in to the adapter. There is power and ground through the cable but not sure if they are going to the right pins in the adapter.
 
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