When I run codes, I get no communication with Body Control Module. Also codes U1160-U1176 & U1164. Could this be a ground problem? If so, which ground.

 

Had a dead battery lately or disconnected it? If yes then clear the codes and read them again after a day or so.

A dead or very low battery will throw a loss of communication code.

 

Thanks. Will do.

 

Clear your codes, then pull them again. Post the code numbers for the BCM and so on. I agree totally with Blue_92...low battery will do this easily.

 

Can someone tell me how to pull the codes. I have no idea how to start. Thanks.

 

The IPC display, the 20-character, vacuum florescent screen above the steering column that says "Corvette by Chevrolet" every time you turn on the key is a powerful device.

DIY Service Techs are going to be most interested in the LPG’s ability to show diagnostic trouble codes (DTC) for all the modules that transmit them.

The "diagnostic display" mode is entered with the following Procedure: Page 8-500

1) Turn on the ignition but don't start the engine.
2) Press the "reset" button to turn off any warning messages
3) Press and hold "options" and
4) While holding "options", press "fuel" four times within a 10-Second period.

For each module, all DTCs will be displayed. If none are present in a module, you will see "no more codes" on the ICP display.

There are two kinds of DTCs, "Current" and "History," designated with a letter suffix, "C" or "H". A current code indicates that the malfunction is present in the system whose module is displaying data. A history code indicates a problem existed in that module sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it is possible it's evidence of a previous problem. Now solved, that was not removed by clearing codes. More likely is that a history code indicates an intermittent malfunction.

"Intermittent" are the most challenging DTCs. An intermittent may have happened only once, may have happened more than once but is inconsistent in its appearance or may be happening on a regular basis but not at the time the IPC is displaying codes. History codes can also be caused by a current malfunction in a system that is not Operating at the time DTCs are displayed. An example is the rear window defogger, which doesn't operate until the BCM detects engine rpm.

For history codes set by a system that does not operate with the key on and engine off, a special diagnostic tool called a "scan tester is necessary to properly diagnose the malfunction.

Once the IPC has displayed all 11 modules, the system goes into the manual mode, which allows selection of each module, using combinations of DIC buttons. The manual mode can also be entered at any time during the automatic sequence by pressing any button except "E/M".

Once the IPC displays "manual diagnostics", you may select a particular module by pressing the OPTIONS button to go forward or the TRIP button to go back.

Once a system is selected and a DTC is displayed, if more than one are present; press GAGES To move forward or FUEL to go back.

To exit the diagnostic mode at any time, press E/M. If you want to erase or "clear" codes, press RESET.

Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory.

 

Pulled battery over night. When I reconnect, hood light will flicker on for 1/10th of a second then off again, never to come back on until I disconnect & reconnect. I had battery check at Auto Zone. It's still good. I can here a click for ground point on right side fender. Checked it for corrosion. It had none. Stumped and frustrated.

 

Frustrated over what? You have not posted a specific problem. Are the no communication codes history....current, etc? Have you tried resetting the codes?

What does the underhood light have to do with what you are troubleshooting?

 

I am having trouble with ignition. I have no power from key in starting position. I have also lost power to light under hood, truck release, and lights to HVAC/Radio, etc. Other things work OK such as power windows, power seats, and lights on speedometer cluster. Running codes says no communication with BCM.

 

So what have you checked? Fuses? BCM for moisture? Do you have a DMM? Can you read schematics if provided?

 

After I cleared codes, I still get no communication with BCM plus U-1160 (loss of communication with LDCM) & U-1176 (loss communication with RFA) What is RFA? I have checked & repaired bare wires in accordion on left door. I have checked fuses, grounds at battery and on right hand fender. I have checked all fuses & relays. I do have a digital multi-meter & can somewhat read a schematic.

 

Did you clear the codes after you re-installed the battery?

http://www.corvettepics.net/misc/c5codechecklist.xls

 

Yes. It was after battery was re-installed.

 

I gotta tell you, when you are trying to help someone, and you have to ask questions twice....it gets a little taxing. So again, any moisture on or around the BCM.

 

With April 15 just around the corner, I think you may be a little over taxed already. Thanks anyway for your help, but I'll keep seeking help from members that are no so troubled when dealing with a simpleton like myself.