U0101 and u0100

Normal Operation The wrench reconfigurable telltale can be turned on by any one of three modules. The powertrain control module (PCM) provides the electronic throttle control status, the transmission control module (TCM) provides transmission status and the four wheel drive (4WD) control module (if equipped) provides a status of the 4WD system to the instrument cluster. Each module monitors the powertrain for their respective function and provides the instrument cluster with the operating status over the high speed controller area network (HS-CAN) communication bus. When a fault condition exists in any of the monitored systems, the PCM, TCM or 4WD (if equipped) control modules provide the instrument cluster with a message to turn on the wrench warning indicator.
If the electronic throttle control message is missing or if the data is deemed invalid by the instrument cluster for greater than 5 seconds, the instrument cluster sets DTC U0100 and defaults the wrench reconfigurable telltale ON. If the O/D off message is missing or invalid for greater than 5 seconds, the instrument cluster sets DTC U0101 and defaults the wrench reconfigurable telltale ON. If equipped with 4WD and the 4WD status message is missing or invalid for more than 5 seconds, the instrument cluster sets DTC U0102 and defaults the wrench reconfigurable telltale ON.
NOTE: If U0100 is set in the instrument cluster other symptoms may also be present such as an inoperative speedometer, tachometer or temperature gauge. If U0101 is set, other symptoms may include the O/D off indicator ON. If DTC U0102 is set, other symptoms may include the 4x4, 4x4 LOW or 4x4 AUTO reconfigurable telltales may be inoperative.

Possible Causes
• Electronic throttle control concern
• Transmission concern
• 4WD concern (if equipped)
• Instrument cluster

the p1682 for pontiac is an ignition problem https://www.700r4transmissionhq.com/pontiac-g6/ as to the u0101 that can be related this code can pop up with a low voltage problem to tcm failure https://repairpal.com/obd-ii-code-u0101-lost-communication-with-tcm

Do you know what U code's Are ? Do you have service info. ? Any module on the vehicle can cause a no start , GMLAN Hi & Lo .
2016 Traverse No start GM Lan A sensor that is on the 5 volt ref. circuit could bring down the Data bus . Your best bet , take your vehicle to a guy like in the video . Before you repalce parts you don't need , plus the BCM would need to be programmed . Anti-theft system - key's would need to be programmed too.

You'll need to get a good auto electrician to look at this. The codes suggest a failed ECU, the brain reading all the engine sensors. If this fails, the car is unusable as the ECU won't let the vehicle work.
Codes read as:
U0073 - Control Module Communication Bus "A" Off
U0100 - Lost Communication With ECM/PCM "A"
U0101 - Lost Communication with TCM
U0121 - Lost Communication With Anti-Lock Brake System
(ABS) Control Module
U0155 - Lost Communication With Instrument Panel
Cluster (IPC) Control Module
I have very little experience with gearboxes so I can't really help with the 3rd gear problem.

This is common in the Nissan's could be the cam and crank sensor these go at around 70000 to 120000 should do both at once to be safe. that will fail an emissions test for sure. hope this helps

U0100 - Lost Communication with ECM/PCM "A"
U0155 - Lost Communication with Instrument Panel Cluster (IPC) Control Module
U0101 - Lost Communication with TCM
All of them are Geniric Codes 4 Mazda, I would say who ever was working on the car last, posobly forgot or missted 1 or 2 connection
plugs along the way near the last repairs. So just trace yr last steps 2 see if ther any unpluged connectors, cos looks like they all are part of same chane in that line.
P2187 - Sys To Lean at the idle Bank 1
Hope that helpes you. Good luck.
Tony D:-)

look it up your self, and see how to do more tests to find
what it fails. in the book,


https://suzukipitstopplus.com/Products/1035-2008-forenza-reno-service-manual.aspx

4 bucks.

U0100 means lost of communication with ECM/PCM
U0101 means lost of communication with TCM

U0100 is lost communication with the PCM (on board computer that controls everything) the U0101 is no communication with the TCM (transmission Control Module. I have read where a lot of people have had no luck trying to fix this and the delaers charge big bucks for it. typically the problem starts shortly after being jump started or having to jump start someone else and hooking the cables up properly. it can also just happen over time which is another of the many reasons i hate new cars. one fix i saw was to remove the positive battery cable and let it sit for 15-30 minutes then ground the positive cable out for 20 seconds before reconnecting it to the battery again, this may not work and if it doesn't it will require either the TCM be replaced or the dealer to have to dig into your car and charge you big time for the work. hope that helps

little side note i have seen some of these error messages cleared up by cleaning up the ground contacts for the TCM and even one fella had some luck replacing the speed control sensor in his and the lights all went away and it ran fine after that.

co327 is a code for your transfer case encoder motor and the U codes are communication codes. Most likely cause is the encoder motor needs replacement