MAP calibration fails

[koracing]

On 7/15/2023 at 3:43 AM, Adamw said:

This was different in G4+ which could end up with a zero offset stored from a previous calibration that would cause subsequent cal to fail

It must have been with a G4+ I had to use that trick then...

On 7/14/2023 at 9:34 PM, Brian B said:

I tried this, I had to blow into the vacuum line to trick the map to calibrate, once it had I then tried to re-calibrate and it failed again. 

Power supply to the ecu, and sensor as well as good grounds can make a bit of a difference in how accurately the sensors read.  Is it possibly you have a grounding issue?

[Brian B]

Did check both sensor ground and sensor 5V, both good 

[jdniss]

On 7/15/2023 at 8:43 PM, Adamw said:

@jdniss I think you should get your ECU back to Link for inspection, I suspect your MAP sensor is probably faulty, in your log the voltage on AN Volt 3 is a good 50mV or 10Kpa higher than it should be.  Contact [email protected] to arrange.

No problems, thanks for looking into it.

[Adamw]

@Brian B I suspect in your case the built-in "Link 3 Bar" calibration in the firmware might be wrong.  At least with the little bit of testing I done today I was getting low values reported by PC Link vs what I calculate from voltage using the manufacturer's transfer function.  I just asked the Firmware team to confirm so I will come back to you when I have an answer. 

[Adamw]

@Brian B We looked at this closer today.  There is a bit of error at the high end of the calibration range but it is much less significant than I first thought and im not sure if it is enough to cause your calibration issue.  I notice your 5V output is sitting a little lower than normal too which may be some of the error.  

Can you try a custom linear cal like below to see if it passes MAP cal with this.  If it doesnt can you go around and unplug a few of your other sensors to see if the 5V output voltage gets closer to 5.00V (it was reading 4.96V when your map was last saved).