fluid pressure value for analog input sensor display is extremely inaccurate

K-Series Programmable ECU installation questions / support issues
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RAIN H8R
Posts: 32
Joined: Wed Sep 14, 2011 3:00 pm
Location: Waukesha, WI

fluid pressure value for analog input sensor display is extremely inaccurate

Post by RAIN H8R »

- what vehicle you have 2001 S2000
- serial number of your K-Pro
- version of software being used 4
- KManager version 4.3.2
- the calibration (as an attachment)
- when and where you got the K-Pro Bought Kpro 4 new 2 months ago

Gentlemen,

I am having issues with the analog inputs for my oil and fuel pressure sensors. Once the engine is running, the values are several hundred digits higher than they should be, far exceeding the reading range of the sensor itself. I am using the AEM brass and AEM stainless steel 0.5v to 4.5v sensors. Both fuel and oil pressure sensors display extremely high pressure values on the kpro sensor display (see screenshot). I have a gaugeART can gauge wired into the ECU CAN H and CAN L, oddly enough the can gauge displays what would appear is a normal value to be seen when the car is running (engine oil pressure is around 100, and fuel pressure is around 50psi on a cold start). This leads me to believe a mathematical formula is incorrect for analog inputs displaying a "custom" calibrated fluid pressure sensor.

Conditions:
Engine off, ignition on, in my garage around 59 degrees. Power for 5v sensors from a Voltage regulator off fuse box set at 5v, feeding a junction block for all 5v sensors. All 5v sensors grounded to 5v ground pin on ecu. Battery voltage is 12.2v.

An4 engine oil pressure aem brass 30-2131 3 wire 0-150psi. Kpro reads 0.00-1.3psi with -.02 voltage offset, voltage is 0.5. Voltage table is 0.5=0, 4.48=150psi. WITH ENGINE RUNNING ON COLD START:, kpro reads 1340psi (not a typo)

An5 fuel pressure aem ss 30-2130 3 wire 0-100psi. Kpro reads 0.0-0.1.0psi with -0.01 voltage offset. voltage is 0.5. Voltage table is 0.5=0, 4.49=100psi. WITH FUEL RUNNING CONSTANT AND ENGINE OFF: kpro reads 584psi (not a typo).

Thank you for your time,
Dustin
Attachments
fuel pressure is reading high.jpg
fuel pressure is reading high.jpg (323.38 KiB) Viewed 5928 times
kpro4 wiring rev5.png
kpro4 wiring rev5.png (637.87 KiB) Viewed 5928 times
Last edited by RAIN H8R on Thu Mar 16, 2017 5:43 am, edited 1 time in total.
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Hondata
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Re: fluid pressure value for analog input sensor display is extremely inaccurate

Post by Hondata »

I know this is not obvious, but the custom values for pressure are in bar.

So enter 0.5V = 0 bar and 4.49V = 6.8 and it should be ok.
Hondata
RAIN H8R
Posts: 32
Joined: Wed Sep 14, 2011 3:00 pm
Location: Waukesha, WI

Re: fluid pressure value for analog input sensor display is extremely inaccurate

Post by RAIN H8R »

Thank you, the sensors read out correctly now.

You should add that to the kpro help screen for analog pressure inputs
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Hondata
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Re: fluid pressure value for analog input sensor display is extremely inaccurate

Post by Hondata »

Yes, we did that for the S300 but not the KPro, so will address it.
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Boostjunky
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Joined: Sat Dec 09, 2023 3:02 pm

Re: fluid pressure value for analog input sensor display is extremely inaccurate

Post by Boostjunky »

Does this formula hold true for AEM brass sensors 35-2131 also? And does the pressure range of the sensor affect anything when programming the analog inputs for those sensors? Thank you in advance!
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