Help finding atmostpheric pressure scaling in ECUflash

laz0r · **Joined:** Thu Jun 02, 2016 6:46 pm **Posts:** 17

dschultz wrote:

Do you have a wiring diagram of were it connects to the ECU, what pin does it come in on?
The scaling for the Secondary Air Piping Pressure (P244) is at address 0xC0298. You can use the same table def as the ATM sensor and play with the scaling to see what affect it has.

I do see code where the SAP pressure and ATM are intermixed and this is probably where the on-board ATM sensor value is replaced with the SAP reading when the SAP is defined to be installed on the engine. Which means there may be a way to delete the usage of the SAP sensor and get the code to use the on-board ATM sensor instead.

Sweet as. I changed that secondary air piping pressure at the above address and it works.
But now since you've suggested it, it would be nice to try make it read the internal atmospheric pressure from the ecu, if the sensor is still on there that is. It could be a good fix for all the people removing secondary air pump valves.

I've attached a screenshot from the service manual, do you reckon this would be the same diagram used for most models, or do they change things around quite frequently?

welaish · **Joined:** Tue Apr 29, 2014 12:48 am **Posts:** 946

laz0r wrote:

welaish wrote:

Well I deleted the Air Pump and I had to cut the sensor out of its housing to and connect back to the plug that goes to the ECU harness. I used the car for a couple of days until I was able to cut the sensor.

Yep thats what I would have done except my pressure sensor was playing up.
Are those pictures the ones you've actually taken? Just looks like thats just the valve only having 2 pins. Just thought you may have cut up the wrong valve, since there is 2 of them.

Pretty sure mine has 5 pin, 2 for the valve, 3 for the sensor.

No that's a generic pictures from the internet. it was 3 pin socket.

laz0r · **Joined:** Thu Jun 02, 2016 6:46 pm **Posts:** 17

dschultz wrote:

I do see code where the SAP pressure and ATM are intermixed and this is probably where the on-board ATM sensor value is replaced with the SAP reading when the SAP is defined to be installed on the engine. Which means there may be a way to delete the usage of the SAP sensor and get the code to use the on-board ATM sensor instead.

What software do you use to see all the code, I wouldn't mind checking it out.

dschultz · **Posted:** Wed Aug 17, 2016 10:11 am

laz0r wrote:

But now since you've suggested it, it would be nice to try make it read the internal atmospheric pressure from the ecu, if the sensor is still on there that is. It could be a good fix for all the people removing secondary air pump valves.

First you need to know the internal sensor is still present and working. For that you'd need to log the sensor.
You can add this code to your Logger def to try it out. Paste it in on a new line before: <ecuparam id="E1" name="IAM*"

Code:

                <ecuparam id="E2000" name="Atmospheric Pressure Sensor Scaled (4-byte)*" desc="E2000-Atmospheric Pressure Sensor Scaled (4-byte)" target="1">
                    <ecu id="4B04505207">
                        <address length="4">0xFF5CDC</address>
                    </ecu>
                    <conversions>
                        <conversion units="psi" storagetype="float" expr="x*0.01933677" format="0.00" />
                        <conversion units="bar" storagetype="float" expr="x*0.001333224" format="0.000" />
                        <conversion units="mmHg" storagetype="float" expr="x" format="0" />
                        <conversion units="kPa" storagetype="float" expr="x*0.1333224" format="0.000" />
                    </conversions>
                </ecuparam>

dschultz · **Posted:** Wed Aug 17, 2016 10:22 am

laz0r wrote:

dschultz wrote:

I do see code where the SAP pressure and ATM are intermixed and this is probably where the on-board ATM sensor value is replaced with the SAP reading when the SAP is defined to be installed on the engine. Which means there may be a way to delete the usage of the SAP sensor and get the code to use the on-board ATM sensor instead.

What software do you use to see all the code, I wouldn't mind checking it out.

viewtopic.php?f=40&t=6303

Or you can use the GNUSH bin tools to dump the code. Not as pretty as IDA.
https://gcc-renesas.com/

laz0r · **Joined:** Thu Jun 02, 2016 6:46 pm **Posts:** 17

dschultz wrote:

First you need to know the internal sensor is still present and working. For that you'd need to log the sensor.
You can add this code to your Logger def to try it out. Paste it in on a new line before: <ecuparam id="E1" name="IAM*"

Code:

                <ecuparam id="E2000" name="Atmospheric Pressure Sensor Scaled (4-byte)*" desc="E2000-Atmospheric Pressure Sensor Scaled (4-byte)" target="1">
                    <ecu id="4B04505207">
                        <address length="4">0xFF5CDC</address>
                    </ecu>
                    <conversions>
                        <conversion units="psi" storagetype="float" expr="x*0.01933677" format="0.00" />
                        <conversion units="bar" storagetype="float" expr="x*0.001333224" format="0.000" />
                        <conversion units="mmHg" storagetype="float" expr="x" format="0" />
                        <conversion units="kPa" storagetype="float" expr="x*0.1333224" format="0.000" />
                    </conversions>
                </ecuparam>

Done this, but it wasn't looking promising.
I had a reading of -2.90psi, since that is what the offset for the atmospheric pressure sensor scaling is set to, I assume there is 0V reading on the input, therefore it does not exist. Agree?

dschultz · **Posted:** Thu Aug 18, 2016 5:12 pm

laz0r wrote:

Done this, but it wasn't looking promising.
I had a reading of -2.90psi, since that is what the offset for the atmospheric pressure sensor scaling is set to, I assume there is 0V reading on the input, therefore it does not exist. Agree?

I suspect you are right.

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