is there a voltage sensor somewhere?
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MBWorld Fanatic!
Joined: Dec 2006
Posts: 1,105
Likes: 11
From: Toronto, Canada
2019 C300 Wagon; '75 Triumph TR6; previous: 2004 C230 6spd sold after 17 years of driving
is there a voltage sensor somewhere?
I hate starting a new thread but as opposed to people that have the Alt/Batt visit workshop malfunction everything on my car checks out to specs
My message is intermittent, sometimes it comes on right away and other times I can drive for 20 minutes and stop and start the car and it does not come on. My battery is 4 days old OEM
I did some checking with my voltmeter and here are the specs at the battery
engine off 12.93v
engine idle 14.08V
engine 2000rpm 14.30V
at the time there was not Alt/Batt visit workshop warning and later the message came on but the above values did not change (maybe by 0.01-0.02V)
Same test but with blower and lights, radio etc all on
engine off 12.93v
engine idle 14.05V
engine 2000rpm 14.26V
Since these results are actually good and within specs, this would indicate that the voltage reg is fine and the alternator is good. Which leads me to wonder if there is some wonky sensor somewhere that is throwing bad voltage messages? Do I need to clear the PCM or disconnect the battery and start fresh and let the PCM reprogram itself?
My message is intermittent, sometimes it comes on right away and other times I can drive for 20 minutes and stop and start the car and it does not come on. My battery is 4 days old OEM
I did some checking with my voltmeter and here are the specs at the battery
engine off 12.93v
engine idle 14.08V
engine 2000rpm 14.30V
at the time there was not Alt/Batt visit workshop warning and later the message came on but the above values did not change (maybe by 0.01-0.02V)
Same test but with blower and lights, radio etc all on
engine off 12.93v
engine idle 14.05V
engine 2000rpm 14.26V
Since these results are actually good and within specs, this would indicate that the voltage reg is fine and the alternator is good. Which leads me to wonder if there is some wonky sensor somewhere that is throwing bad voltage messages? Do I need to clear the PCM or disconnect the battery and start fresh and let the PCM reprogram itself?
