S300v2 shows 300F for IAC/ECT after capacitor upgrade

[Raf99]

Hi,

H22 prelude engine in a 93 accord. In good measure I sent the ECU to a professional to have the capacitor replacement kit installed before they failed. Now I get this (see picture). Car never moved, worked fine before the repair. I tried re-seating the S300 board. The ECU solder joints look fine, professionally done but no warranty on the work as the ECU is old. I know the guy, he is legit. And he actually cleaned up a lot of the sloppy solder joints done by the company who sold it to me. But........ I'd like to have a working car again :( I'm not looking to blame anyone, just want my car working again and just wondering if anyone has seen this before?

Obviously car will turn over and start for a second but no MAP...



A section of his cleanup job. Well done.

[Hondata]

Check the connectors for any bent pins. Check you have 5V on the VCC1 and VSS2 pins in the ECU. Then check the MAP connector for 5V on the VCC1 wire. This will narrow it down. The other possibility is that a sensor has shorted and is pulling the VCC down to GND, so unplug the IAT and ECT and see is that changes the MAP. Also check the ECU ground on the thermostat housing.

[Spunkster]

Has J12 been cut?

[forevertrj]

The header pins are too deep after the rework, if you did a continuity test from the back of the ECU to the top of each pin on the hondata board I'm positive you would find either one side is fully open circuit and if you tilt the board the other side would go open circuit, do a continuity test on each pin and let us know if you find any open circuits, if you do find open circuits, try removing the black header pin holder on the top side of the ECU that is under the hondata board, remove the hondata board, get a hair drying and heat up the plastic just so it's warm and you can pull up on it to remove it. basically if the header pins are seated too deeply into the board the black plastic will prevent the pins from seating into the Hondata female header fully. I know this because i had this exact issue. Obviously the proper fix is to have the 14 pin rails reseated but that's a lot of work and will cost you money from the sounds of it.

[forevertrj]

also do a continuity test on each of the data log pins from ECU to hondata that one is at the usb port and is 4 pins. Also when the the Hondata board has a map installed and is communicating with the ECU you should Have a solid green light at the USB B type connector.

[Raf99]

Thanks. I got things working again by cleaning up the board and re-heating the S300 solder joints.

[forevertrj]

So when you did a continuity test from the back of the board to the top of the hondata board terminals the was continuity? But the pins on the board just weren't fully soldered? Did you push the male header pins up at all?

[forevertrj]

Also if the board sealant was removed I would spray new water proofing silicone sealer on the board so no corrosion builds up. Just looks like it was removed in the second picture the board doesn't look Shiny with the water proof coating.