[JFM-jr]

I licensed my FSCM in my camaro with the sole intention of gaining access to the DTC tables contained in it and disabling the AFM valves DTC's . I was successful with the write as there is no CEL for the AFM valves after they were removed and driving the car a few days now. These DTC's are the ONLY parameters I changed in the FSCM when I did the write using the "Supplied stock file" that HPT generates as the actual file from your car can not be read via the OBD we can only write to it. Instead when you select to "read" the FSCM a stock file that is generated by HPT is what you get. You makes your changes and write calibration. My question is now when looking at the tables in the FSCM "supplied stock file"(there are not many) there are tables with different values than the ECM has when comparing them to what appear to be duplicate tables also found in the ECM.
Open Loop DC table FSCM#6997 / ECM#6970
Pressure Sensor Offset table FSCM#6989 / ECM#6977
Pressure Sensor Gain FSCM#6990 / ECM#6978
ill include screenshots to show what im seeing.
Im wondering if this supplied file values are correct the big question is should I change them to match the ECM values or leave it. There were a few tables that did indeed have matching values. I know the rewrite worked (No CEL) but along with the simple DTC changes I also am at the mercy of HPT having all the stock information correct in the file they generate. Some screen shots you will see in the tables its notated whether its the ECM of FSCM module the table is for.

[JFM-jr]

I believe I am on to something here with my thoughts. I have a friend who is a GM tech and he looked up the wiring diagram. The low side pump is controlled by the FSCM and the High side pump is Controlled by the ECM. This would explain having the same tables in each module with different values. For instance the battery volts vs fuel rail pressure table has the FSCM side populated and the ECM side all zeros. Low pressure pump is driven off voltage and high pressure side is driven off the camshaft (hence the zeros). This thought process lends credence to everything else as well.

[DSX Tuning]

The reason for the discrepancy is that Camaros with the electronic diff (and consequently all C7s) control the fuel pump through a slave pump driver via the powertrain expansion CAN bus. Because of this, the ECM reads fuel pressure directly as the low side sensor is connected to the ECM.

On the non electronic diff Camaros, the chassis control module runs the fuel pump. The fuel pressure sensor is directly wired to the CCM as is the fuel pump.

I wouldn’t change the values.

[JFM-jr]

Thank you sir!

Originally Posted by DSX Tuning

On the non electronic diff Camaros, the chassis control module runs the fuel pump. The fuel pressure sensor is directly wired to the CCM as is the fuel pump.

I wouldn’t change the values.

So this goes with my thinking on my non E LSD that both the low pressure pump and its sensor are connected to the FSCM and the high pressure pump and sensor is ECM controlled.

[DSX Tuning]

Yes. Anything high side related is ALWAYS handled directly by the ECM. E-diff cars use a dummy slave module to run the low side pump. It gets a duty cycle request from the ECM via CAN, and the low side pressure sensor is wired directly to the ECM.

[JFM-jr]

Originally Posted by DSX Tuning

Yes. Anything high side related is ALWAYS handled directly by the ECM. E-diff cars use a dummy slave module to run the low side pump. It gets a duty cycle request from the ECM via CAN, and the low side pressure sensor is wired directly to the ECM.

Thank you for the response very much appreciated and clears up my needless confusion