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Voltage

smdandb2

smdandb2

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Hey Guys, just curious as to what voltage you are seeing in your Ecoboosts?

Mine is all over the place. I actually suspect there is an issue.

There are times I am driving for 20-30 miles and it sits at 12.3V and I have seen it as high as 15.2V.

It hasn't caused any malfunction lights to illuminate, but it certainly seems off to me.

I love this car, but it certainly has its annoyances. Mine came with factory body work that was done pretty shittily that I just noticed the other night. I contemplated going to the dealer and bitching, but I don't think I want them to dink with the paint on a metal panel that can't be replaced.

Either way, curious if this voltage issue is mine alone or if it is normal for these cars.

Thanks.
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DickR

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Justin,

My GT's voltage display is similar in regard to unexplained voltage variations compared to what we would normally expect including going below 12 volts when the engine has been off for several hours without the lights or radio on. However, reading the voltage in the console power point using a volt meter indicates "normal" voltage. Based on a detailed review of the factory service manual CD my guess is that the combination of the "voltage display circuitry/logic" and the "battery charge control" system is resulting in "strange" voltages compared to what we normally would expect. Modern charging systems do things a lot differently than in the past, I think, and I suspect that the voltage display isn't intended to be a "real voltmeter".

I did mention this to the service manager and also the owner (who is an SCCA racer) of the small dealership where I bought the car as a "heads up".

In my case this is the ONLY "problem" with my car in 2 weeks and 800 miles. I suspect it really isn't a problem other than to customers who pay close attention like us. Who knows, there may be a "software fix" at some point.

Dick
 
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smdandb2

smdandb2

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DickR said:
Justin,

My GT's voltage display is similar in regard to unexplained voltage variations compared to what we would normally expect including going below 12 volts when the engine has been off for several hours without the lights or radio on. However, reading the voltage in the console power point using a volt meter indicates "normal" voltage. Based on a detailed review of the factory service manual CD my guess is that the combination of the "voltage display circuitry/logic" and the "battery charge control" system is resulting in "strange" voltages compared to what we normally would expect. Modern charging systems do things a lot differently than in the past, I think, and I suspect that the voltage display isn't intended to be a "real voltmeter".

I did mention this to the service manager and also the owner (who is an SCCA racer) of the small dealership where I bought the car as a "heads up".

In my case this is the ONLY "problem" with my car in 2 weeks and 800 miles. I suspect it really isn't a problem other than to customers who pay close attention like us. Who knows, there may be a "software fix" at some point.

Dick
Click to expand...
Dick,

You nailed it. I finally decided to actually hook up my accessport and check out the live gauges. Sure enough, voltage on the AP was much more reasonable. At one point I saw a 1.5v difference from the MFD to the AP. I'm not sure what Ford was thinking when they coded that, but I'm glad it's not a real problem.

I'll leave it hooked up for a day or two just to log charge air temps, as I'm curious how bad they are even in subzero temps.
 

DickR

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smdandb2 said:
Dick,

You nailed it. I finally decided to actually hook up my accessport and check out the live gauges. Sure enough, voltage on the AP was much more reasonable. At one point I saw a 1.5v difference from the MFD to the AP. I'm not sure what Ford was thinking when they coded that, but I'm glad it's not a real problem.

I'll leave it hooked up for a day or two just to log charge air temps, as I'm curious how bad they are even in subzero temps.
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Torque also gives more reasonable results at both the adapter and at the control module (ECU?). :)
 

JJ@WMS

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The vehicles alternator output is computer controlled. There is nothing wrong with your car.

There are several tables for commanded voltage and some of them are in the 12.3 range or so during normal driving.

JJ
 

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The voltage can appear to go haywire at various times but for good reason. There are times when your alternator will not actually be charging the battery because of the parasitic drag that it creates and resultant drop in MPG. The alternator system is designed to get the battery to a target state of charge, and not overcharge or undercharge it. This has been introduced on a lot of late model cars for MPG purposes. It's all good!
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