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I've looked but maybe I've missed it. The programming I've found voltage (not sensor) are all related to the FICM, but when you look at the voltages in AutoEnginuity there is also a location for battery voltage, a fourth value. When you display on AE there are variations between battery, FLP and FICM main power. But if you observe readings off SG when a FICM is wonky, it makes it look like battery voltage is an issue, when in fact it isn't.
I've think I've cleaned up some of the signal by disconnecting and reconnecting the three connectors to the PCM which has improved the SG readout, but it's still not equal to the AE or using a fluke off a cabin power port. (I won't even bring up battery terminal vs the others.)
So anyone ever find the programming for battery volts?
If I remember right, I'm using the gauge that was pre-programmed into the scan gauge but I did find this Xgauge.
BAT 07E0221172 046205110672 3008 000100010000 BATTERY VOLTAGE
It's not uncommon to get slightly different voltage readings on different parts of the same circuit, even a simple circuit with one power supply and one load. Of course finding a connector with a significant difference on each side would be an indication of a problem.
I'm not the one who originally programmed this SG so I'm not sure if these values were preprogrammed. What I'm trying to sort out is when someone states an alternator is an issue due to this voltage reading when all other tests either by component or other data source (AE / IDS) does not.
I'm not the one who originally programmed this SG so I'm not sure if these values were preprogrammed. What I'm trying to sort out is when someone states an alternator is an issue due to this voltage reading when all other tests either by component or other data source (AE / IDS) does not.
It sounds like you're suspicious of the ScanGauge reading, and I guess I would be too in that situation. I suspect what could be making the difference is whether the device is measuring the value and displaying the results or asking the PCM what the voltage is and displaying that answer. Of course measuring voltage supplied to the FICM would be a different answer than measuring the batteries with a meter. Different size and legnth of wire, number of connections, and the load on the circuit could change the voltage reading.
And that SG reads in steps along with adjustable update rates.
An example of the variations I've seen on AE. Scaling is off between the FICM and battery values so you have to consider that. Since I can't use both SG and AE at the same time, my only relation can be SG to Fluke and then Fluke to AE and pray the operational values haven't changed much during the switch.
This isn't as bad as I saw before I "wiped" the PCM connectors, or I'm just observing what I want to believe.
