More Codes - Help Needed

[BLEUBYU]

In a previous post I had asked about getting rid of a PCM that would cause me to fail emissioons testing. I decided to take one responder's advice and have the original tuner (a very well regarded company) reprogram the PCM. I sent the PCM to them and received it back last week. So far there are no PCM codes although I am still not sure how many GM drive cycles it will take to allow emissions testing.

However, today I noticed a bunch of history codes that I never had before. First, what are they - and second, will any of them affect safe operation of the car or emissions?

Here they are:

58 SDM 2 codes - U1000H and U1016H

A0 LDCM 2 codes - U1016H and U1096H

A1 RDCM - 2 codes - U1016H and U1096H

B0 RFA 2 codes - U10906H and U1016H.

I realize thses are all history codes and some of them are the same despite being listed separately.

Thanks in advance for your help. I suppose these can be gotten rid of by doing a "Reset"?

For years, no codes - now it is getting a little crazy!

[No Doubt]

SDM = Sensing and Diagnostic Module
LDCM = Left Door Control Module (drivers door)
RDCM = Right Door Control Module (passenger door)
RFA = Remote Function Actuator (key fob)

"U" is an OBD network code and indicates a loss of communications as follows:

U1000 Loss of Communication Undetermined
U1096 Loss of Communications with IPC (Instrument panel Cluster)
U1016 Loss of Communication with PCM (Powertrain Control Module)

None of these codes are emissions related and will not affect emissions compliance or the safety of the vehicle.

[RocketSled]

Originally Posted by No Doubt

None of these codes are emissions related and will not affect emissions compliance or the safety of the vehicle.

Not only that, but they are quite common. It's a "weakness" of the design. The car's computers are all networked together, and communications errors are to be expected. They will happen when you disconnect the battery, and sometimes even just while you're cranking the engine.

GM should have written their software better, to be more tolerant of this type of error so they don't get reported as easily. More retries before giving up, for instance.

When they appear as "H" codes, they are 100% "Don't Care".

[No Doubt]

They will happen when you disconnect the battery, and sometimes even just while you're cranking the engine.

As well as when one is uploading a 'tune' for example. The various modules are always active and if for any reason they are not able to 'talk' to one another across the bus a U code can be generated.