My check engine light keeps coming on. I can clear them, but they just keep coming back. The codes that trigger it are:

U1016 Loss Of Communication with PCM (No SOH Message Received)

U1064 Loss Of Communication with DCM (No SOH Message Received)

U1096 Loss Of Communication with IPC (No SOH Message Received)

These codes started (I believe, though I'm not saying they are a result of) shortly after installing a Halltech TRAP air intake. I also have access to ls1 edit, but as far as I know, these codes cannot be prevented by a tune. Besides that, the car runs fine and shows no sign of a problem. If anyone knows what could be causing these, and most importantly, what I can do to alleviate the problem, I'd appreciate it. Thanks.

-Brett-

 

sounds like something is not connected tightly or possibly a short somewhere on one of the sensor plugs but I am no expert..

 

Check your battery voltage, if you start the car and the voltage drops to below 10-11 volts it will trigger those codes.

 

Weak battery. Mine does this from time to time if I let it sit too long.

 

I've never seen my battery voltage below 13 volts. It's usually around high 13 or low 14. And these codes trigger pretty often, not just from having it sit a day or two. Do you still think it's the battery?

 

Watch it while you crank the engine.

 

Here is the deal!! If your battery is weak and the reserve voltage is LOW, when you crank the car, the starter draws an A$$ load of battery current. Battery voltage is inversly proportional to battery current in that voltage tries to go low as current draw goes HIGH! If your battery is weak it goes TOO LOW!

Take your battery to one of the big name Auto Part stores (Advance, Auto Zone ect ect...) and have them check the battery for cold cranking amps and reserve cranking voltage. If it shows that the battery is questionable,, get a new one! Recommend a Optima Red Top!


Your modules are very sensitive to low voltage. If one of the modules drops below 9.5 VDC for even a micro second they will shut down temporalily and error out with a U series code. As soon as the voltage come back up to above the 9.5 vdc threshold, it worke normaly again. That is why the DTC codes are all HISTORY and do not affect any thing that you can detect.

There are a few more issues that can cause the "U" series codes to error out. If you have a loose or bad connection on one of the modules. The DCM (left especially) is very suseptable to causing other modules to erroe out with a U code.

This just happened to me while I was at Carlisle PA. The door electrical cable connection had a loose connection and the door control Module died! I disassembled the door and just pulled on the wiring harness that goes through the accordian tube between the door abd the body and now everything is working. I am going to have to disassemble the entire connector and check for bad pins and do a pull test on the female pins to get to the bottom of this issue.

Bill C