I am getting this message as a diagnostic code for RTD HVAC and SCM. Is this typical or is there a problem?

 

RTD: Real Time Damping, your car may not have this option so NO Comm would fit.

HVAC: Heating Ventilation Air Conditioning should have comm and no codes

SCM: Seat Control Module should also have comm and no codes.

 

Sometimes I get the no comm for my HVAC system. It happens the same time my HVAC system does not work (doesn't come on). Is sounds like those systems have a power or ground issue. That's what I'm looking into for my HVAC problem.

Below is a list of what each ground point is for (someone else posted this on the forum). Good luck

G101 left front frame (with SP101)
G102 right front frame (with SP100)
G103 left front of engine
G104 frame next to battery (with G108 & SP102)
G105 left lower engine block, engine ground strap & wire
G106 Battery negative pole
G107 Left rear head
G108 frame next to battery (with G104)
G201 bottom of A-pillar, left (with SP201 & SP203)
G202 bottom of A-pillar, rt, bolted at the bottom (with SP202)
G205 inside door pillar driver seat (with G301)
G301 inside door pillar passenger seat
G302 inside door pillar driver seat (with G205)
G401 left rear outer frame
G402 right rear inner frame
SP201 bottom of A-pillar, left (bolted with G201)
SP202 bottom if A-pillar, rt (bolted to G202)
SP203 bottom of A-pillar, left (taped to wire bundle, with G201 coming out of it)
G101: windshield washer fluid pump
Windshield washer fluid level switch
Brake fluid switch
Headlamp door assembly, left
G102: cooling fan, right
Cooling fan 3 relay 44
Horn assembly
Underhood lamp
Headlamp door assembly, right
Headlamp door control module
A/c compressor clutch
A/c compressor clutch diode
Secondary air injection pump
G103: Electronic brake control module (ebcm)
G104: battery negative pole
Splice pack SP102:
Marker lamp, right front
Marker lamp, left front
Park/turn signal lamp, right front
Park/turn signal lamp, left front
Turn signal lamp, right front
Turn signal lamp, left front
Splice pack SP208:
Body control module (bcm)
Instrument panel cluster (ipc)
Data link connector (dlc)
Inflatable restraint & diagnosis module
Inflatable restraint ip module disable switch
Park/neutral switch
Remote control door lock receiver
G105: fuel pump relay 35
Engine oil level switch
Heater O2 sensor, bank 1 sensor 1
Heater O2 sensor, bank 1 sensor 2
Heater O2 sensor, bank 2, sensor 1
Heater O2 sensor, bank 2, sensor 2
G106: battery negative pole
Ignition relay 42
Powertrain control modules (pcm, 4 wires)
Throttle actuator control module (tac)
Mass airflow sensor (maf)
G107: ignition control modules 1-3-5-7
Ignition control modules 2-4-6-8
G108: Electronic brake control module (ebcm)
G201: Splice pack SP201:
Data link connector (dlc)
Air temperature actuator
Instrument panel cluster (ipc)
Traction/suspension control switch
Driver door module (ddm)
Door latch, driver
Auxiliary power outlet
Windshield wiper motor
Steering column lock
Footwell courtesy lamp, left
Instrument panel cluster (ipc)
Hazard switch
Telescopic actuator switch
Splice pack SP203:
Remote CD changer
Fuse block I/P
Speaker, right door
Speaker, left door
Radio
G202: Splice pack SP202:
Passenger door module (pdm)
Door latch, passenger side
Body control module (bcm)
HVAC control module
IP compartment lamp
Footwell courtesy lamp, right
Vanity mirror lamp, left
Vanity mirror lamp, right
Inside rearview mirror
Bose relay 45
Ignition switch
Blower motor relay c60
Blower motor control processor
Hood ajar switch
Cigar lighter
A/t shift lock control solenoid
G205: seat belt switch, driver
Seat control module (scm), driver
Seat pump, driver
Seat belt switch, driver
Seat relay center, driver
G301: defogger grid
G302: Splice pack SP302:
Seat relay center, passenger
Seat pump, passenger
Rear compartment courtesy lamp, right
Rear compartment courtesy lamp, left
Rear compartment lid latch
Rear compartment lid latch, right
Rear compartment lid latch, left
Folding top lid latch
Folding top release switch
Fuel door lock actuator
Radio power antenna
G401: Splice pack SP400:
Fuel pump & sender assembly, left
Fuel level sender, right
Tail, stop, turn signal, rear left
Tail, stop, turn signal, rear right
Center high mounted stop lamp
Backup lamp, right
Backup lamp, left
License lamp, right rear
License lamp, left rear
Marker lamp, left rear
Marker lamp, right rear
G402 electronic suspension control module (esc)

 

Thanks for all the responses. I ran out of time and needed to get the car repaired, so off to the dealer. The condition was related to the initial starting of the car and the power delivered to all electrical components. The Fix was a new ignition switch. This has fixed a variety of problems including the blower randomly turning off an on and the mysterious back up lights. Crispy21 this should be of particular interest to you since we seemed to have the same condition. The cost of the part is $75.00 (#10308321 for my 97)from the dealer and $275 in labor... This also took care of the O2 sensor codes, all 4, and a series of coded related to communications. After all my research and the problems I thought it could be, I still feel lucky. If I can help let me know...

VMI07

 

Hmmmm, that is interesting. I wonder how they diagnosed that. After reading your update last night, I checked this morning to see if my back-up lights worked while my AC was out. Well sure enough they didn't work. About 15 min. later my AC was back on so I tested my back-up lights again and they worked. I only have one more ground to check but I'm pretty sure that its fine. Sounds like we are having the same issues. I would of never thought to check my back-up lights.
I'll have to try to find a way to test the ignition switch. Thanks for the info.

 

your welcome and good luck. I would post a separate post on checking the ignition switch. All is still fine with mine..

VMI07

 

I want to extend a big thanks to VMI07 for letting me know what your solution was to the problem we were both experiencing. I was going to start changing out the computer(s) and HVAC units to try to fix my problem with the HVAC. But I figured I would try to replace the ignition switch first which you said worked for you. Plus it was only a $40 part. Well I replaced the ignition switch over the weekend and my HVAC has been working flawlessly the past couple of days. It wasn’t difficult to switch out. The hardest part was figuring out that some of the connectors can’t come off unless the key is in and turned on.
Thanks again for sharing the information. It helped save me lots of time and money because I would have never thought of the ignition switch.

 

The research acquired form consumer response has proved to GM, and, the service techs at local Chevrolet dealerships that, indeed, faulty grounds, a loosely connected and failing battery, as well as, faulty ignition switches (common problem), are more often than not, the culprits to many of the electrical gremlins that develop in the Corvette C5.

The affected systems and symptomology range from non comm. reading SCM, SDM, BCM, and, HVAC issues, to inoperative O2 sensors, faded LED readouts, twitchy back up lights, and, unusual hatchback ajar messages, etc. Glad everything worked out for those affected by the faulty ignition switch.

Best Wishes,
Eden