I have been occasionally getting the dreaded EBCM code 1214. It occurs only at start up. I have cleaned the EBCM grounds.

My battery is 7-8 years old. When my battery is on a CTEK maintainer I don't get the codes. The code appears at startup after I let it sit for a few days between starts. When I look at my voltmeter gauge during starting, the voltage drops to the minimum 8V on the gauge. From what I have read the fault code C1214 occurs when the voltage drops to 8V. The car starts fine but turns over a little slow.

When the car starts the code C1214 doesn't go away. I have to turn it of and clear the code.

Before I take the EBCM off for repairs I was wondering if this is caused by a weak battery or is this just symptomatic of a failing EBCM power relay.

Thanks in advance for your replies.

 

100%

To prove the bad battery theory,, put a DC Volt Meter on the battery terminals and have someone crank your engine. Observe the LOWEST voltage on the meter. I’ve seen battery voltage at the output terminals drop as low as 9.5 VDC during cranking and still crank and start the engine. HOWEVER,,,,,,,,, if you examine your DTCs when this happens you will see a whole host of HISTORY DTCS, and U series DTC..

The U series DTCs indicate that the module did not or was not able to report state of health to other modules In other words, it dropped off line while it was under voltage.

When you first engage the starter, it draws it MAXIMUM AMPERAGE. As the engine starts to spin and cylinders start to fire, the starter uses less and less amperage until the engine starts and you release the key and go to run.

Battery voltage is inversely proportional to battery current.
When you throw high current at the starter to crank the engine, battery voltage will go LOW. If you have a weak or aged battery the cell plates cannot provide the voltage necessary to support proper electrical module operation.

Its tough to say if the battery is a direct result of the 1214 DTC BUT,,,,,,,,, its a fact that relays DO NOT operate properly when supplied improper voltage & modules do not operate at all under a specific low voltage cutoff. I believe its 9.5 VDC.

Replace that battery! You and your C5 will be a LOT happier.

You DO NOT need a $200 fancy battery. I purchased an Autozone Premimum battery and my ZO6 is working excellent.

 

a low battery in these cars can set just about every code. First thing you must do is determine if the battery is 100%.Listern to Uncle Bill.

 

I replace the batteries in my cars after 5 years even if they are still good. Trying to sqeeze an extra year or two out of them is asking for problems. Why would you even consider messing with the EBCM before you replace your 8 year old battery?

 

The most common cause of the 1214 is a little relay popping off the breadboard when its solder joints fail. With that being said, it is very likely that low battery voltage would exacerbate that condition as now you have a high-resistance, partial-contact point at the relay terminals when the solder joints loosen up.

It will fail completely at some point and no amount of battery voltage will help. Fix it sooner rather than later. Chances are the relay is fine and you just need to reflow the solder.

Forgot to say: My car did the exact same thing. I would get sporadic 1214s that would clear after driving awhile. They got more and more frequent over time. Replaced the battery, thought all was well for half a year or so, then the code came back and stayed put. Pulled out the brake control module, replaced the relay (prob just need to resolder and not replace, but i'd already ordered the relay), and all has been well for about a year now.

 

I've had two Optima red tops and each time, after 5 years, when I started the engine, the DIC display would go to "ODOMETER" instead of the "Gages" I had showing before the engine was shut off. I think this is the way a C5 shows its battery is almost gone. Anyone agree or disagree?

 

The dic defaulting the the odometer setting does seem to be common with a failing or weak battery.

 

100% on the mark. Weak /failing battery or a power issue.

Bill

 

Get a battery. But the ebcm relay is bad and WILL need replacing. It will eventually go out. The ebcm is easy to remove and fix.