Can't upload - ECU doesn't see Ignition on

jsoman · Post by **jsoman** » Mon Jul 25, 2005 11:37 am

I have the "Hondata racecar" wiring harness that had worked fine until I removed the ECU and drivetrain from the car. I have not been able to upload a calibration because the Hondata program and ECU don't see the ignition on when it is.

I've checked for the voltage on the #9 pin on the ECU E connector and
it's got the 12 volts. The USB connection seems to fine. Is there anything else I should check?

Thanks,

John

Post by **Spunkster** » Mon Jul 25, 2005 1:27 pm

Check the ground in the engine bay...especiallteh the one normally on the manifold.

Razathorn · Post by **Razathorn** » Mon Jul 25, 2005 1:33 pm

I don't know if this is related, but it's food for thought. One of my laptops loses connection to kpro quite a bit. The other is rock solid. I know my grounding is good, I ran additional grounding to the block and frame from the neg terminal and relocated the injector/ecu grounding to the head (same as new ground wires). I tested it with an ohm meter to make sure I didn't have any weak connections as well.

Perhaps using a car adapter to power your laptop (instead of just battery) would equalize ground across the laptop and car and prevent usb communication breakdown if that is the case. I've seen grounding differences play havoc with networking and the same principal could be at play here.

Just a thought.

Post by **Hondata** » Mon Jul 25, 2005 2:44 pm

Check that E7 is getting grounded by the ECU when the ignition is switched on. If not, the main relay output transistor has been damaged or the main relay is not wired correctly.

jsoman · Post by **jsoman** » Mon Jul 25, 2005 8:16 pm

E7 is getting grounded by the ECU when Ign. is on and the relay is wired correctly. I guess the main relay output transistor is toast.

Do I send it back to the dealer or directly to Hondata?

Thanks for the feedback guys.

Post by **Hondata** » Tue Jul 26, 2005 8:52 am

If E7 is getting grounded then check that the main relay is switching on (A2 / A3 should get 12V with the ignition on). You never said - is the ECU running the car?

jsoman · Post by **jsoman** » Tue Jul 26, 2005 11:00 am

Ok, I'll check that the main relay is switching on (A2 / A3).
The ECU is running the car.

Post by **Hondata** » Tue Jul 26, 2005 11:21 am

Ah. If the ECU is running the car, then check that the KPro board is secure inside the ECU. If that looks good; you'll have to send it back to us.

jsoman · Post by **jsoman** » Tue Jul 26, 2005 12:03 pm

Now that I check the communication/Hondata board it does seem to be a bit loose so I will make a delicate effort to better seat it. If that doesn't work I'll send it in.