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Yes, you should have the VCIM module…Onstar is the pay subscription…what is the issue ??…if your scan tool can see the VCIM module and if you can look at live data for it you’re good…do you need the information bus wiring ??…if so A/T or M/T ??…your RPO code will be UE1 I think.
Evidently if you don't have Onstar, then you don't have the VCIM either. The CAN wiring diagram shows that without Onstar, the CAN wiring goes straight thru rather than make a detour to the VCIM.
Evidently if you don't have Onstar, then you don't have the VCIM either. The CAN wiring diagram shows that without Onstar, the CAN wiring goes straight thru rather than make a detour to the VCIM.
I believe Onstar was optional in 2006.
Well I don’t have Onstar but I do have the VCIM module as you can see if my system topology…the module is still there…if you have the microphone on the top of the left A pillar he should have it.
Well I don’t have Onstar but I do have the VCIM module as you can see if my system topology…the module is still there…if you have the microphone on the top of the left A pillar he should have it.
C5Diag, is your car a 2006 model? If so, was Onstar specified at the time of ordering the car new? If you have a build sheet, does it show that your car has Onstar? As I stated earlier, I believe Onstar was optional in 2006. You had to specify Onstar at time of ordering the car, or they would not install the hardware for it. My car is a 2006 Z06 1LZ, and it did not come equipped with Onstar. It does not have the microphone at the top of the left A pillar.
C5Diag, is your car a 2006 model? If so, was Onstar specified at the time or ordering the car new? If you have a build sheet, does it show that your car has Onstar? As I stated earlier, I believe Onstar was optional in 2006. You had to specify Onstar at time of ordering the car, or they would not install the hardware for it. My car is a 2006 Z06 1LZ, and it did not come equipped with Onstar. It does not have the microphone at the top of the left A pillar.
It is a 2008…I have the UE1 RPO code…OK, if OP doesn’t have the MIC then he probably doesn’t have the VCIM…thanks !!
Yes, you should have the VCIM module…Onstar is the pay subscription…what is the issue ??…if your scan tool can see the VCIM module and if you can look at live data for it you’re good…do you need the information bus wiring ??…if so A/T or M/T ??…your RPO code will be UE1 I think.
Thanks for getting back to me C5 Diag. I’m getting U-0121 and U-2108 codes. I’ve check the voltage and clean the grounds and when I measure the Can Bus I get 60.2 ohms and the voltages seem normal. I had the EBCM repaired and am still having the same issues. Which is when started up while the engine is cool everything is fine. After warm up when I start the engine i immediately trip the codes and the ABS light stays on. Let the car cool down for a couple hours and then start it and everything is normal. The only thing I haven’t checked is the connector at the auto trans or the VCIM.
Did you originally have a “no comm” with the EBCM ??…both of those DTC’s are no comms with the EBCM…for a “no comm” for a SINGLE module you want to check the power and grounds…2 grounds and a Run/Crank Ignition 1 voltage and battery voltage…you should back probe all 5 wires and see if the Ignition 1 voltage decreases and your ground “elevates”…should be near 0 volts…yes, you should see around 60 ohms between pins 6 and 14 and around 2.5 volts for CAN high and low…if you know how to do a “terminal tension “ test I would do that since this is intermittent…check those wires after the car warms up…no need to chase the VCIM if you only have those 2 DTC’s !!
Thanks I haven’t checked the Run Crank Ignition 1 circuit I did check the voltage at 3 spots on the EBCM connector. One was the ignition voltage and the other 2 were batt voltages. All three were around 11.8 Vdc not running with the ignition on . I do not know what back probing is. I have a feeling that I’m not getting a wake up signal to the EBCM when starting the engine after it is warmed up. Thanks for your suggestions I’ll keep digging.
Video on back probing below…a modules “wake up” signal is the ignition voltage when ignition is in RUN or START…battery voltage is “keep alive” voltage…the module will retain any learned values with battery voltage…check power backprobing when ignition is in RUN and then see how much it drops when the engine is started comparing it to the battery voltage…should only drop .1-.2 volts.
Video on back probing below…a modules “wake up” signal is the ignition voltage when ignition is in RUN or START…battery voltage is “keep alive” voltage…the module will retain any learned values with battery voltage…check power backprobing when ignition is in RUN and then see how much it drops when the engine is started comparing it to the battery voltage…should only drop .1-.2 volts.
Ok so here is my next question if no one minds, Since I don't have a VCIM and I'm positive I don't. The Class 2 can runs from the BCM to the Splice pack and from there to the VCIM. What module does it connect to for cars without a VCIM? I have a automatic 6l80 and I don't have Electronic suspension control so my guess is it must go to the TCM T43 connector but I'm not sure. I'll have to crawl under there and check.
If there is no VCIM there would be no wire on connector H (light green wire) at SP208 if that is what you’re asking….information bus for A/T below…as I mentioned if resistance and voltages are good on the bus and you are getting those U codes check powers and grounds.
Sounds good, I'll check power and grounds again especially after it's hot and also SP208. Thanks for all your help
No need to check the splice pack...I mentioned if you don't have the VCIM you won't have that light green wire on SP208...you will only have it if you have the UE1 RPO code that will be found on the sticker in your glovebox....not the issue for your EBCM No Comm.
I think I might of finally figured this problem out. It is the under the hood fuse box. Fuse 3 ABS/MRRTD 10A Ignition 1 circuit sends 12volts to the EBCM when the ignition switch is turned on. That voltage is missing after the fuse box gets warm or hot. I'll know for sure tomorrow.
VCIM Question for a 06 base
