[Gmecm] gm 5300 OBD2 port wiring

[WopOnTour]

Not on THAT truck in 2002. First LD truck application using CAN (GMLan) was 
the 2004 PHT (Parallel Hybrid Truck). The 2005s STILL dont. Although there 
have been numerous GM cars and sprot-utes that use GMLan since 2003.
WOT
----- Original Message ----- 
From: "DV Fagan" <dvfagan at yahoo.com>
To: <gmecm at diy-efi.org>
Sent: Saturday, March 12, 2005 11:56 PM
Subject: RE: [Gmecm] gm 5300 OBD2 port wiring


> Steve,
> It is possible that GM is using differential
> signalling which requires two leads.  That might
> explain the common coloring.  I would assume the
> signals are asynchronous meaning start bits should be
> discernable on an oscilliscope or serial data link
> analyzer.
> They might be CAN buss.  It is getting popular.
> Dennis
> --- Robert Fleming <robert.fleming at sbcglobal.net>
> wrote:
>> There are 2 UART wires right next to each other with
>> the same color.
>>
>> There are also 2 wires that go to the ecm that are
>> labelled as class 2 serial data.  It does not say
>> high or low.  Anyone know which one goes where on
>> the diagnostic link?
>>
>> Steve Ravet <Steve.Ravet at arm.com> wrote:
>>
>>
>> ________________________________
>>
>> From: gmecm-bounces at diy-efi.org
>> [mailto:gmecm-bounces at diy-efi.org] On Behalf Of
>> Robert Fleming
>> Sent: Thursday, March 10, 2005 2:36 PM
>> To: gmecm at diy-efi.org
>> Subject: [Gmecm] gm 5300 OBD2 port wiring
>>
>>
>> I'm looking at a 5.3 swap and am running into some
>> problems on
>> the OBD2 diagnostic port wiring. It is a 2002 5.3
>> and the FSM pinout
>> says that pins 14 and 15 are UART serial data and 58
>> is class 2 serial
>> data. Now I assume at the least the UART serial data
>> pins are high and
>> low, but the problem is they are both orange and
>> black. And does the
>> class 2 serial data use the vehicle chassis ground
>> as its low? The
>> harness that came with the engine had the chassis
>> side chopped off, so
>> tracing wires doesn't answer the question.
>>
>> Any help is appreciated.
>>
>> Thanks,
>> Robert
>>
>>
>>
>> Robert, you might find that the 2 UART wires are the
>> same signal in 2
>> different cavities. The schematics should show if
>> this is the case.
>> class2 is referenced to ground. what are you
>> swapping into?
>>
>> --steve
>>
>>
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>
>
>
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