Serious problem...

DC5RK20A · Post by **DC5RK20A** » Sat Jul 28, 2007 12:33 pm

Yesterday, well early Saturday morning I noticed something a little strange, when I had the laptop plugged into the ECU the communication by USB would go away and I would get a clicking noise. Not sure exactly what the problem was. Well tonight (early Sunday morning) as I went to connect the laptop because I wanted to do a datalog, again the clicking immediately started and I got a CEL, I disconnected the laptop from the USB cable and drove to meet some friends, the CEL was still on. At a red light, I reconnected the USB cable to try and retrieve the error code, but the CEL started to dim in and out and the car then shut off. I restarted the car with the USB connected and the CEL came back on, light turned green, started to move forward and then a distinguishable electronic burn, I immediately disconnected the USB cable and the car turned off. Pulled to the side of the road and yanked the ECU. I then opened the cover of the ECU to see what fried, the daughterboard's biggest chip in the center was toast. The ECU cover also has a burn mark where it sits above the fried chip. I will include some pictures. What do I do now? I had to remove the daughterboard to even fire the car up and be able to drive it, which is now rev-limited to 3900rpms and I have no way to retrieve the error code as when the daughterboard is replaced back in and I connect the USB to my laptop, it doesn't respond.

Is there the possibility of getting a new daughterboard and any ideas as to why this suddenly just happened? The only thing I changed recently(on Thursday afternoon) was swapped my PRC intake manifold for a RBC manifold.

RSXSnail · Post by **RSXSnail** » Sat Jul 28, 2007 7:40 pm

did u ground your cable ?

did u leave ur USB connected to Hondata all the time ?

DC5RK20A · Post by **DC5RK20A** » Sun Jul 29, 2007 4:41 am

RSXSnail wrote:did u ground your cable ?

did u leave ur USB connected to Hondata all the time ?

Which cable, the USB cable? I don't believe so, but I am going to look at the cable and see what's up with it. I have always left the cable plugged into the back of the ECU, pretty much can not unplug and plug it in when the ECU is mounted in place.

Post by **Hondata** » Mon Jul 30, 2007 8:52 am

Yes, the KPro can be replaced if damaged. We'll need both the ECU and KPro as often the ECU serial port can be damaged with this type of problem.

The cause of the damage is a interruption to the ground path from the ECU to battery. The normal path is from the ECU through to the master ground on the intake manifold, then to the cylinder head, then to the engine block, then through the timing cover (or transmission) ground to the chassis, then to the battery. If any one of these grounds is missing or has a high resistance, then the current that the ECU is sinking finds some other way to flow to the battery - via the USB cable in your case. The ECU sinks considerable current (10 - 20 amps) so these grounds are ciritical.

abdultaiyab · Post by **abdultaiyab** » Mon Jul 30, 2007 9:03 am

so earthing kits are a good idea while upgrading to kpro??

DC5RK20A · Post by **DC5RK20A** » Mon Jul 30, 2007 2:02 pm

How much money am I looking at for replacement? Also the car is driveable with the daughterboard out, of course I have a 3850rpm limit and CEL on. So I am guessing the ECU is still good. Is there any way at all that I can just send in the daughterboard and have a new daughterboard sent out? I am only allowed one vehicle here and with my work, my car is used extensively, so I really can not be without a vehicle for too long. If it is not possible, then I guess I will have to try to figure something out.

About the grounds, well I have each ground you mentioned in place and on top of that a grounding kit adding additional grounds to the valve cover and IM. Have to go check each ground today after work and see if something is up.

Post by **Spunkster** » Mon Jul 30, 2007 2:57 pm

You must call us for an RMA number and you will have to send the ECU and K-Pro in. IT will be a minimum of $350 for a replacement K-Pro which includes the $100 diagnostic charge. THis assuming your ecu is still ok. IF the eCU is also bad, it will be an additional $100 to install the K-Pro board into an ecu you supply.

DC5RK20A · Post by **DC5RK20A** » Mon Jul 30, 2007 3:22 pm

How long will the turn around be? Remember I am in Japan, even doing express shipping will take at least 3 days to get to you. You all doing USPS Priority Express will take an additional 3-7 days to get back to me. This is why I was wondering if the daughterboard can just be sent out and I send in the crapped out daughterboard. At least right now I can drive the car in the rev-limited mode, so that tells me the ECU is fine. If not, then I am looking at up to 2 weeks downtime. Anyway I can email you all for the RMA #?

DC5RK20A · Post by **DC5RK20A** » Mon Jul 30, 2007 9:51 pm

Still wondering about emailing you for the RMA number. And if I can't email, what is the phone number, can't find anything on the site. What is the best time to call, I'm 16 hours ahead?

Post by **Hondata** » Tue Jul 31, 2007 9:26 am

Email support@hondata.com or call 310 782 8278 9-5 PST.

DC5RK20A · Post by **DC5RK20A** » Fri Aug 10, 2007 2:31 am

Uggghhh, I think I found the problem. Today I picked up a couple more grounding wires to go with the kit I already had. Figured why not, won't hurt to have a few more. Come to find out, the main ground that I installed, a 2 gauge cable from the battery to the chassis was not really connected. The wire that was crushed into the cable ring had come lose and was only held together by the electrical tape, but was not making contact with the ring holder. This had to be the cause as all the other grounds looked fine.

I also picked up a stock R ECU online here and it should be arriving any minute now. Once that is installed I will be sending my ECU out, so hopefully sometime next week it will arrive at Hondata.

Post by **Hondata** » Fri Aug 10, 2007 9:10 am

You don't need a grounding kit. They do not help.

You just need these grounds:

- main loom G101 to cylinder head
- cylinder head to chassis
- transmission to chassis
- battery to chassis

The last two are the only wires which carry any current (for the starter); the other ground wires don't need to be thick.

DC5RK20A · Post by **DC5RK20A** » Fri Aug 10, 2007 8:23 pm

Well so much for me buying a stock ECU, come to find out the newer R has a different ECU even though inside it looks all the same. I am trying to do something with the buyer as right now I have a $400 paper weight. So it will be some more time before I can send off my ECU. :x :(

DC5RK20A · Post by **DC5RK20A** » Sun Aug 19, 2007 7:31 am

Well I got another stock ECU another $400 spent and low and behold it is a 37820-PRC-013 even though the seller said it was a 023 model and had the Honda wrapping with that model # on it in the picture :evil: , which is for the very first DC5 before some tiny revision in April of 2003 when the chassis numbers changed and also the ecu model went to 37820-PRC-023. The car will fire up with it in, but stupid me I wasn't thinking, a stock ECU is not really going to work for me, I have 510cc injectors...which means FUEL DUMPING with the 310cc stock mapping. Well I will throw in some used plugs and just cruise the car at low rpms as I have gotten somewhat accustomed to with the 3785rpm rev limit I currently have with my ECU.

A question to Hondata, when I do send in my ECU to have a new daughterboard installed, would you mind if I also sent in another ECU and you checking to see if it can be KPro'd? It is also a PRC ecu, but it is from the facelifted ITR and has a model number of 37820-PRC-J01. Installing this in the car and the car will not fire up, it cranks but will not turn over. I opened it up and the board is the same exact board as the other 2 PRC ECUs, but I am unsure if the pinouts are the same. I figure if it can be KPro'd then I could possibly sell it to somebody stateside that needs an ECU to get KPro installed, best for those that have a leased vehicle and can't really get it. Also I noticed your list of ECU's doesn't list this model ECU, maybe because you never had one in your possession, but I would be willing to let you test it, hahaha, willing to...more like it would possibly be a win win for both your company and myself.

Post by **Hondata** » Sun Aug 19, 2007 4:40 pm

The PRC-J can be used. It has an immobilizer like the US ECUs, so it will not start the engine.