Question Details

I changed out alternator and recharged batteries, the car seems to charge and turn on powered consumers at regular idle. but when idles higher they shut off. when turn car off and let sit it starts fine and everything works. once idles high does again? what do you suggest

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MBFanatic  1 year 6 months ago

Let me see if I understand your question correctly. Are you saying that the "electronic consumers" get turned off at regular idle? Once the idle / RPMs are increased that error goes away?

If that is the situation, it sounds that the alerantor is not working properly or it is not generating enough voltage. I would have a shop check the alternator or check the voltage yourself. If you live in us, Advance Auto or Autozone will test the alerator for free. Have you done that yet?

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Visitor  1 year 6 months ago

yes I have now resolved all the issues and it is now at a point where it runs fine I test the voltage , all is well for few minutes the the electrical consumers are shut off and the charging stops. could the computer need to be told the components are fixed, relay, or fuses?

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MBFanatic  1 year 6 months ago

I don't think that any control units need to be programed. I would set it up on a voltage test unit. Advance and AutoZone will test it for free if you live in US. Otherwise find a shop that has star diagnostic scanner and have them read the codes.

My guess is that there may be an issue with the voltage regulator. Also how old are you batteries?

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Visitor  1 year 6 months ago

all are brand new. could it be the bcm

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MBFanatic  1 year 5 months ago

That's possible but the Battery Control Module rarely goes out. What year is your E Class? If you have a secondary / aux battery, that could be causing this problem as well. If you have a trickle charger or any charger that puts out anywhere from 2 A to 10 A (12 volt) I would charge the secondary battery. Also do an alternator test. Read the codes as well. You don't want to replace an expensive BCM and it turns out its not the problem.

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Visitor  1 year 5 months ago

solved it was a shorted connection !!!