Electrical “gremlins”
Thread Starter
Instructor
Joined: May 2024
Posts: 216
Likes: 15
From: Uniontown Ohio
Electrical “gremlins”
I am getting codes sporadically on my 2019 z06 referring to losing communication to tcm p0073 and u0073, I am able to reset codes and car is ok, for days at a time
i have an aeroforce guage which is how I am reading and resettting codes,
I took the car to the local dealer to have them look deeper into some of the codes I can’t see and they see several items they are going to look at on Friday
one of the odd things I seen is when the cel comes on the aeroforce guage flashes as if to reboot, since these codes seem to be more along the “lost communication” line I am curious if the aeroforce guage or the aem wideband that are connected to the obd2 port could be the source of these problems
just wondering if anyone has ever had something attached to obd2 cause an issue
thx
i have an aeroforce guage which is how I am reading and resettting codes,
I took the car to the local dealer to have them look deeper into some of the codes I can’t see and they see several items they are going to look at on Friday
one of the odd things I seen is when the cel comes on the aeroforce guage flashes as if to reboot, since these codes seem to be more along the “lost communication” line I am curious if the aeroforce guage or the aem wideband that are connected to the obd2 port could be the source of these problems
just wondering if anyone has ever had something attached to obd2 cause an issue
thx
Pro
Joined: Nov 2021
Posts: 515
Likes: 187
From: Pittsburgh, PA
I had some weird electrical issues in the past. I resolved them by disconnecting the battery overnight then connecting it back up the next day. This resets the CAN bus systems as well as the modules and my issues went away. When the CAN bus sees less than 5v it can cause issues that won't go away until the system is reset. Worth a shot
Thread Starter
Instructor
Joined: May 2024
Posts: 216
Likes: 15
From: Uniontown Ohio
Thanks for the tip,
I have not disconnected for that long since back in winter during cam install but as you say can try again,
I drove to Florida and back (from Ohio) via tail of dragon and then Myrtle beach and back with no incidents , then a few times in the last couple weeks here in Ohio ,
maybe car just don’t like it here up north , time to move I guess :-)
I have not disconnected for that long since back in winter during cam install but as you say can try again,
I drove to Florida and back (from Ohio) via tail of dragon and then Myrtle beach and back with no incidents , then a few times in the last couple weeks here in Ohio ,
maybe car just don’t like it here up north , time to move I guess :-)
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,561
Likes: 4,030
From: Cape Coral, Florida
I am getting codes sporadically on my 2019 z06 referring to losing communication to tcm p0073 and u0073, I am able to reset codes and car is ok, for days at a time
i have an aeroforce guage which is how I am reading and resettting codes,
I took the car to the local dealer to have them look deeper into some of the codes I can’t see and they see several items they are going to look at on Friday
one of the odd things I seen is when the cel comes on the aeroforce guage flashes as if to reboot, since these codes seem to be more along the “lost communication” line I am curious if the aeroforce guage or the aem wideband that are connected to the obd2 port could be the source of these problems
just wondering if anyone has ever had something attached to obd2 cause an issue
thx
i have an aeroforce guage which is how I am reading and resettting codes,
I took the car to the local dealer to have them look deeper into some of the codes I can’t see and they see several items they are going to look at on Friday
one of the odd things I seen is when the cel comes on the aeroforce guage flashes as if to reboot, since these codes seem to be more along the “lost communication” line I am curious if the aeroforce guage or the aem wideband that are connected to the obd2 port could be the source of these problems
just wondering if anyone has ever had something attached to obd2 cause an issue
thx
There is a TSB related to all these aftermarket devices plugged into the DLC !!...they can cause communication issues (U codes).
Last edited by C5 Diag; May 22, 2026 at 11:50 AM.
Thread Starter
Instructor
Joined: May 2024
Posts: 216
Likes: 15
From: Uniontown Ohio
So it sounds like my wideband and aero force guage could be a contributing factor,
the dealer has it today and one thing that was discovered was a bad speed sensor on the right front which I might have messed up lowering the cradle during my cam install, I am letting them fix that then clear all the codes pertaining to communication and voltage
I have removed the wideband and guage for now and will drive for a while and see how it goes, if all stays good I would like to find another way to have that type of guage and wideband without causing problems
thx for the tsb info
the dealer has it today and one thing that was discovered was a bad speed sensor on the right front which I might have messed up lowering the cradle during my cam install, I am letting them fix that then clear all the codes pertaining to communication and voltage
I have removed the wideband and guage for now and will drive for a while and see how it goes, if all stays good I would like to find another way to have that type of guage and wideband without causing problems
thx for the tsb info
Advanced
Joined: Feb 2009
Posts: 72
Likes: 8
From: Texas
Not C7 application but I sold my Aeroforce gauges years ago because they caused issues like this. They are a bidirectional tool so they can interfere with CANBUS signals causing gremlins and U (communication) trouble codes.
OBD plug in devices tend to drain batteries when car is off causing further problems. Adding AGM battery into the mix only makes it worse since they charge different than lead acid.
OBD plug in devices tend to drain batteries when car is off causing further problems. Adding AGM battery into the mix only makes it worse since they charge different than lead acid.
Thread Starter
Instructor
Joined: May 2024
Posts: 216
Likes: 15
From: Uniontown Ohio
That does make a lot of sense, especially since I see that guage do a reboot when done if the incidents happen,
It is really convenient in the fact I can reset codes with it but if it is the main reason I am getting codes what is the sense,
I just replaced my aem obd wideband with one with no guage and analog output which the aero force reads,
if I could find a guage I could plug into obd to read the ethanol and read the analog of the wideband but only read the obd that seems like it would not cause as much issue other than battery drain which I could deal with
i am going to drive a while without anything connected to obd and see if any occurrences
any suggestion in a guage
It is really convenient in the fact I can reset codes with it but if it is the main reason I am getting codes what is the sense,
I just replaced my aem obd wideband with one with no guage and analog output which the aero force reads,
if I could find a guage I could plug into obd to read the ethanol and read the analog of the wideband but only read the obd that seems like it would not cause as much issue other than battery drain which I could deal with
i am going to drive a while without anything connected to obd and see if any occurrences
any suggestion in a guage
Last edited by acs3931; May 24, 2026 at 11:40 AM.
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Advanced
Joined: Feb 2009
Posts: 72
Likes: 8
From: Texas
I don't understand the point of your gauges reading through the OBD port. All of my wideband are AEM dedicated gauges. They do not feed PCM any data on my setups as of today. If it feeds the PCM and you want to monitor AFR, the gauge itself should suffice.
One of my cars has ethanol content feeding through an emissions device so that signal does go through the ECU/PCM to the handheld tuner plug in device. It still drains the battery while parked for days or weeks if left plugged in. That car is not GM though so not apples to apples comparison.
Does your setup repurpose existing sensors for E content and wideband AFR? Can you simply switch to standard gauges that do not read through the OBD port? Perhaps the caveman solution is simply unplugging it while parked?
One of my cars had a stack of dedicated modules to read several data sets but the bulk and wiring was a nightmare. IIRC it was an old PLX system. I think they have improved on the physical configuration since.
One of my cars has ethanol content feeding through an emissions device so that signal does go through the ECU/PCM to the handheld tuner plug in device. It still drains the battery while parked for days or weeks if left plugged in. That car is not GM though so not apples to apples comparison.
Does your setup repurpose existing sensors for E content and wideband AFR? Can you simply switch to standard gauges that do not read through the OBD port? Perhaps the caveman solution is simply unplugging it while parked?
One of my cars had a stack of dedicated modules to read several data sets but the bulk and wiring was a nightmare. IIRC it was an old PLX system. I think they have improved on the physical configuration since.
Thread Starter
Instructor
Joined: May 2024
Posts: 216
Likes: 15
From: Uniontown Ohio
The most popular wideband is an odb unit that plugs into the odb port with a pass through plug that allows the hp tuners dongle to be plugged in and read afr while remote tuners do tuning, but the second solution is 5v output that can be read by a guage or hp tuners etc.
Most of the current flex fuel sensors for our c7 z06 plug into the ecm and the alcohol content is read by the ecm and any device that can read obd such as banks gauges
or areroforce etc,
I am replacing the obd wideband unit with one that has 5v output that will connect directly to the aero force guage as you mention to read afr and can connect directly to the hp tuners for remote tuning, so no need for odb in the wideband loop, therefore the aero force will be the only item connected to obd, I have read that the aero force can be an issue if there are other items plugged in.
Most of the current flex fuel sensors for our c7 z06 plug into the ecm and the alcohol content is read by the ecm and any device that can read obd such as banks gauges
or areroforce etc,
I am replacing the obd wideband unit with one that has 5v output that will connect directly to the aero force guage as you mention to read afr and can connect directly to the hp tuners for remote tuning, so no need for odb in the wideband loop, therefore the aero force will be the only item connected to obd, I have read that the aero force can be an issue if there are other items plugged in.
Last edited by acs3931; Yesterday at 02:49 PM.