rochoa21

Was driving got reduce power, low fuel, tcs, car then shuts off, Tried to restart the car a bunch of times and nothing. It turns over. I add gas to the car, check all fuses, theres fuel pressure. Still nothing, get home after the car gets towed and find the following codes.

C1276H
U1016H
U1000HC
10 PCM No Comm

Basically theres no communication with the PCM. So now what do I do?
Thanks
Robert

2003 z06

3boystoys

Start checking grounds/fuses/cables/connectors.

rochoa21

All fuses are good, where would I find a diagram of all the grounds

Smoken1

In this sticky by Bill Curlee

http://forums.corvetteforum.com/c5-t...tion-long.html

3boystoys

Search is your friend.

rochoa21

Checked and cleaned grounds 101, 102, 103, 104 and had the battery charged and checked still no luck

RedRiderZR1

First the codes. C1276 has to do with communication with the EBCM and the PCM. Since the PCM is not being seen more than likely that is because of the no comm with the PCM.
U1016 means no comm with the PCM on the class 2 circuit.
U1000 is the basic no comm code that goes with the U1016 code for the PCM.
As was mentioned need to check connectors, fuses and grounds. Check fuses underhood. PCM fuse 16 and PCM B fuse 23. As for the ground it is G106. From what you said above you did not check that ground. From the ground pic I am looking at it seems to be at the engine passenger side. Also check the Class 2 serial buss connections and STAR connectors if the other things mentioned here do not work. Those are 2 thin connectors by the BCM. Check and see if there is any loose wiring or short there. The one with more wires on it is the one you need to check. Looks like 10 wires coming out of it. Only 4 come out of the other one. The wire you would look for would be Dark Green.

Greg

rochoa21

Thanks
Will take a look

rochoa21

I cleared all the codes and this what I get now

58 SDM
U1000HC
U1016HC

40 BCM
1255HC

RFA 1000HC

RedRiderZR1

Throwing more Communication codes. Check the connectors by the BCM. Did it get wet by any chance at the BCM. Try disconnecting the 2 STAR connectors and check for any issues. Then re-connect them. May be some short or loose connection. If wet, that would be an issue too.

One more thing. Are you sure you have a good battery in the car. These cars do strange things with a weak battery. So be sure it has a good charge. and not a bad battery.

rochoa21

Had the battery checked and charged.

Bill Curlee

You either have a CLASS 2 SERIAL DATA BUSS failure or short

OR

You’re missing a power or ground input to the BCM or PCM.

The BCM and PCM are MULTIPLE FUSE supplied. Find ALL the fuses for each module. PHYSICALY remove the fuse and check it with an OHM METER. On top of the fuse are two slots. They are TEST SLOTS.

Use your DC Volt Meter and measure each slot to a known good bare metal chassis ground. The HOT AT ALL TIMES supplied fuses should read full battery voltage all the time

The HOT IN RUN AND START supplied fuses has to have the ignition switch ON to read voltage on those fuses.

You should see FULL Battery voltage on those fuses also.

BC

rochoa21

Found this, looks like someone hacked something could this be the issue?
Also I checked the star connectors they look fine.

Where is the class 2 bus connector and what does it look like?
Thanks

Bill Curlee

Cant view the pictures. Did you host them on something like PHOTOBUCKET??

Bill

Smoken1

Found this, looks like someone hacked something could this be the issue?

You need that it is the LMC5 it prevents the column lock problem

rochoa21

rochoa21

I installed the column lock but that piece of tape with two wires I did not do.

Bill Curlee

Its difficult to tell from the picture but,,,, If the wires are YELLOW, ORANGE and BLACK,, Thats most likely the AUX power wires GM provided you to connect things to. The yellow is switched 20 amp power, the Orange is hot at all times 20 amp power and the black is ground.

The black tape is how they come from the factory Sometimes silver tape.

Bill

robert1989

Here's a question, what mods have been done to your car?

Also in my limited experience as a mechanic I've encountered this on other cars. When the PCM goes bad on say a crown vic you will plug in your scan tool/computer to the car and you will not get any comm with it. The line that does the "comm" between the OBDII is a direct shot from the port to the PCM. I for one have never seen this line broken.

So, with every single fuse, ground and electrical modification double checked and no comm with a non on board scanner. I would start hunting a new one down.

As for this being a Corvette I would say that I had a column lock code on my 1998 C5 I removed the battery for 2 days one time and had it on a trickle charger put the battery back in and the code and warning is now gone. The only thing you have to lose by doing this is your radio stations.

Edit: Also check the power line to the PCM and see if their is voltage, I suspect there will be.

rochoa21

I do not have any mods other than an after market radio and the steering wheel lock disable. I tried to hook up a obd reader but there was no communication.