OPD II Code

[wa7hra]

My OBD II scanner reports an error code of U1300 with no description. Any one know what this code is????

Bob wa7hra

[wa7hra]

My OBD II scanner reports an error code of U1300 with no description. Any one know what this code is????

Bob wa7hra

[DriVer]

I found that the U1300 Code you see is most likely the following:

U1300, U1301, or U1305 Class 2 Data Link Shorted

here's more information:

DTC Network Codes

We see on this page that the DTC you are seeing is also:

U1300 - Class 2 Short to Ground

How that manifests into a resolution to a problem I wouldn't be sure how to advise you other than to see a WSC who can run a Tech II and see what's up!

[RVThere]

I couldn't find anything specific to motorhomes, but in the Corvette world, U1300 is:

U1300 Class 2 Circuit Shorted to Ground

I also found this in a GM Tech Service Manual from 2002 which mentions U1300 at the end of the quote:

No-Start or No-Start/No-Crank complaints
can occur for multiple reasons. However, one
of the reasons can be a shorted Class 2 bus.
Vehicle Theft Deterrent systems utilize the
Class 2 bus to communicate security
information between various controllers. For
instance, the BCM will get information from
the Passlock module and then communicate
with the PCM to allow or disallow fuel
delivery and/or starter enable.
When the Class 2 bus is shorted to either
ground or battery voltage, the controllers are
unable to communicate with each other. This
is because the voltage on the line is held
static at either ground or B+. The Class 2
message toggles the voltage on the bus
between 0 and 7 volts, but when the bus is
shorted, the toggling cannot take place.
Because the voltage remains static at either
ground or B+, the Class 2 message can't be
sent or received.
Without these Class 2 messages being
sent and received, the PCM won't get the
proper security messages which would
normally enable fuel and/or starter enable
and the customer will have a No-Start or No-
Start/No-Crank complaint.
TIP: If the problem is intermittent,
remember to search for the U1300 - Class 2
Data Link Low, and U1301 - Class 2 Data Link
High--in "History". This will help determine the
source of the problem.

Based on this rough info, you may want to check to see if any parts of the wiring harness have rubbed up against the frame and caused a short.

Good luck!

[Carvin Marvin]

If looking for a short or rubbed harness the first place I would look is under the steering wheel That harness crosses a sharp edge. Mine wore through, which would blow the 40 amp fuse when moving the wheel to a down position, the dash lights would go out, the jacks would come up and the start curict is dead. Just a thought Marv

[K6TBC]

Could be caused my Ham Radio gear used in the RV or not. I'm fishing in wy. the Cutts are hitting Grasshoppers on after another.

[wa7hra]

Thanks to all for the replies, and yes, Dan, it could have been caused by some stray RF floating around from 100 watts into an untuned antenna.

Anyway, I deleted the code from the report and we will see if it returns. It may have simply been a transient.

Bob, wa7hra

[wa7hra]

After three or four hundred miles of driving and numerous engine starts and stops, U1300 has not reappeared. I think it's safe to assume it was indeed a transient.

Bob, wa7hra