Service Electrical System
03-20-2017, 05:43 PM
#1
Instructor
Thread Starter
Service Electrical System
I have a2005 C6 Vert z51 manual that started throwing the 'Service Electrical System' message. I reset it and it comes back after a about 5-10 minutes.
I have checked the site and checked the alt sensor fuse - I pulled the fuse and tried honking the horn - when pulled horn doesn't worked but fuse in horn works.
I tested the alternator and it reads 14.3 at idle and 14.2 at the battery. The DIC says 14.2 and when driving it goes anywhere from 14-14.6.
Question - I have read that this is reading electrical draw and when the amps get below the threshold the msg pops up on the DIC.
I also read that it could be the O2 sensors going bad - but wouldn't that throw a code? I do have headers and the front O2 sensor delete by ECS.
Before I spend the cash for a new alternator - anything else I can check?
Should I invest in an upgrade since these cars seem to be very power temperamental - say 170amp or higher?
TIA
Bob
I have checked the site and checked the alt sensor fuse - I pulled the fuse and tried honking the horn - when pulled horn doesn't worked but fuse in horn works.
I tested the alternator and it reads 14.3 at idle and 14.2 at the battery. The DIC says 14.2 and when driving it goes anywhere from 14-14.6.
Question - I have read that this is reading electrical draw and when the amps get below the threshold the msg pops up on the DIC.
I also read that it could be the O2 sensors going bad - but wouldn't that throw a code? I do have headers and the front O2 sensor delete by ECS.
Before I spend the cash for a new alternator - anything else I can check?
Should I invest in an upgrade since these cars seem to be very power temperamental - say 170amp or higher?
TIA
Bob
Last edited by rhoyvald; 03-20-2017 at 05:45 PM.
03-20-2017, 06:38 PM
#2
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Check codes, it's probably just a minor issue. Feel free to call me tomorrow to discuss in length.
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03-20-2017, 08:19 PM
#3
Instructor
Thread Starter
04-23-2017, 12:31 AM
#5
Tech Contributor
I had the problem after I installed an under drive pulley. I turned off the code with HP tuners 10 years ago or so and haven't have any trouble since nor any dead batteries. I suspect the voltage the alternator puts out at certain speeds, and not at idle, is less than the computer expects so it sets a code but that's just a guess. I fooled around with fixes and finally turned off the code. p0621.
Here's my post from 2009 on the subject.
https://www.corvetteforum.com/forums...-system-2.html
Here's my post from 2009 on the subject.
https://www.corvetteforum.com/forums...-system-2.html
Last edited by Joe_G; 04-23-2017 at 12:32 AM.
04-26-2017, 05:29 PM
#6
I had this problem a few years ago... I've heard people say this code came up after installing new spark plugs, which is weird; and other people have had shorted wires under steering wheel, in or near the column. I messed with wiring under steering wheel, found a bad relay under passenger floor board, changed my spark plugs, put a different pulley on alternator to compensate for under drive harmonic pulley, and found a bad plug under drivers seat. One or more of those fixed it, ha....