Not Grounding Main Relay - K Swap S2000

K-Series Programmable ECU installation questions / support issues
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Michigan_Maize
Posts: 2
Joined: Mon Apr 06, 2020 8:37 am

Not Grounding Main Relay - K Swap S2000

Post by Michigan_Maize »

Info:
2002 Honda S2000
K-Pro serial #: 47835
Software Version: 4.3.4.0
ECU Part#: 37820-PRB-A05
ECU Serial #: 2068-513073 0G29
KManager 4.4.2
Calibration attached
K20A2 engine installed in S2000
Ordered K-Pro from Pure Tuning

Working through a K20A2 swap on an S2000. Installed engine and wire harness from same engine. Ground locations are negative battery cable to body, wire harness by injectors to cylinder head, engine block to body, transmission by starter to driver side engine mount. The engine harness needed connectors swapped for the TPS, MAP Sensor, IAT, and VSS swapped to attach to the S2000 intake and transmission. I used a Rywire conversion jumper harness to connect the S2000 C101 Plug to the K20A2 wiring harness C101 plug. This also has an E plug going to the ECU that needs to be tapped into the 32p A Connector and C101 plug from the S2000 as follows:
a. Fuel - E Plug position 1 GRN/YEL = IMO Fuel Pump Relay to S2000 position A15
b. Fan - C101 Plug Position 4 GRN = Radiator Fan to S2000 position A20
c. MIL - E Plug Position 31 GRN/ORN = MIL to S2000 position A19
d. Tach - E Plug Position 27 BLU = RPM Output to S2000 position A19
e. Ground – BLK ring terminal bolt to chassis ground

I had finally gotten this all together and went to initially start the car. I had my laptop connected to the ECU with KManager running. I turned the key to the ON(II) position and remember hearing the fuel pump prime and then noticed my battery was dying. I turned the car off to charge the battery and came back to try the process over. This time I didn't hear the fuel pump prime and in KManager I'm seeing on the bottom On Line, Ignition Off.
So I went back rechecked all my grounds - Good. I confirmed continuity in all the ground lines, confirmed continuity to separate body ground. I unseated and re-seated every connector. I re-spliced all my harness connections. Finally started looking at the PGM-FI relay. First thing in the manual for troubleshooting says "Check for continuity between body ground and PGM-Fl main relay 7P connector terminal No. 3. (Ground)". I do not have continuity here, it is reading open. I tested the relay and it appears to be working.

Did I fry the ground circuit inside the ECU? I have no other vehicle to test this in. Is there another way to bypass this circuit to confirm that it is the ECU?
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Spunkster
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Location: Hondata

Re: Not Grounding Main Relay - K Swap S2000

Post by Spunkster »

Is this a regular K-Pro, or is this a setup specifically modified for an S2000?
Michigan_Maize
Posts: 2
Joined: Mon Apr 06, 2020 8:37 am

Re: Not Grounding Main Relay - K Swap S2000

Post by Michigan_Maize »

Regular K-Pro. Per suggestions from Rywire, I ran a wire from the PGM-FI relay #3 Ground position to a body ground and the car runs great.

Any issues with this? Thanks
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Hondata
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Posts: 10450
Joined: Thu Aug 15, 2002 12:13 pm
Location: Torrance, CA
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Re: Not Grounding Main Relay - K Swap S2000

Post by Hondata »

In a normal vehicle this would power the relay the whole time. We don't know how your vehicle is wired so if it works for you then great, but we can't advise on the wiring.
Hondata
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