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K-Pro 4 MAP Input Failure & Analog Input Bypass Query

Posted: Mon Sep 14, 2026 5:20 am
by Akira
<Symptom>
MAP sensor reading in KManager is stuck at -29.9 psi (0.00V) with "Rev Limit: ON" triggered.

<Confirmed Checks>
・MAP Sensor: Verified functional (voltage responds properly to manual suction/pressure).
・Harness & Wiring: 5V reference, Ground, and Signal wire continuity to the ECU pin are all confirmed. (Jumping 5V to the signal wire still yields no response in KManager).
・Software: Firmware is up to date; re-uploading the base map did not resolve the issue.

<Inquiries>
Since damage to the A19 MAP input circuit or the internal K-Pro 4 ADC is suspected, are ECU inspection and repair services available?

As an alternative bypass, is it safe and recommended to wire the MAP signal directly into one of the K-Pro 4 Analog Input terminals and reassign the MAP input source in KManager?


- vehicle: NB miata swapped with k24a. The engine is from JDM odyssey absolute.
- serial number: 64860
- version: kpro4
- ECU part number:37820-PPA-A58
- KManager version: 4.6.1.0
- the calibration (as an attachment)
- a datalog of a problem (as an attachment)
260912_急にアイドル不調でエンジンがすぐストールする,田邊君MAPセンサー.kdl
- stock miata/ stock engine
- bought kpro4 at KPowerIndustries in 2023 July

Akira Takikawa
Best,

Re: K-Pro 4 MAP Input Failure & Analog Input Bypass Query

Posted: Mon Sep 14, 2026 10:53 am
by Spunkster
Have you tried this ECU on a known working vehicle other than this one?

Re: K-Pro 4 MAP Input Failure & Analog Input Bypass Query

Posted: Tue Sep 15, 2026 4:56 am
by Akira
Thank you four quick response.
I have never tried this ECU on the other working car , so I will try.
This ECU was working properly until 3weeks ago, but suddenly the ECU stopped recognizing MAP signal.

Re: K-Pro 4 MAP Input Failure & Analog Input Bypass Query

Posted: Thu Sep 17, 2026 6:15 am
by Akira
I was able to confirm that the MAP sensor was working after connecting it to an Integra Type R (DC5).

The cause was that the MAP sensor's ground wire was almost broken. Connecting the MAP sensor's ground directly to the body made the MAP sensor work. I'm using a Jackspania engine harness, but it seems to have a tendency to break easily.

Thank you so much for your prompt advice. I'm planning to exhibit the Kswap Roadster at the Honda Yorii factory festival next week, and it looks like I'll be able to finish it in time, so your advice was a great help.