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May have fried my ECU!

Andy5000

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Location
Salisbury, UK
Car
Honda Accord MK 6
Hi guys,

I think i've managed to fry the ECU in my MK6 Accord, but wanted to check if you guys agree if this is the most likely cause!

The engine light came on last week, after a brief stutter during driving. Following the stutter there were a few micro stutters every now and then, but nothing significant so I made my way home. When I got back (late in the evening) I started Googling the issue and found some bloke on YouTube who was demonstrating self-diagnosing engine light codes on his USA-version accord. By shorting two of the connections, you can get the engine light to flash out a series of short/long codes to indicate what the issue is.

I'm driving the UK version, and when I I found the OBD port i noticed the wiring was different, but in a moment of madness, being too impatient to wait until the morning to take it to the garage, decided I'd give it a go regardless... nothing obvious happened, but when I turned the ignition the engine light was now off. The car will crank, but not start. There is no sound of fuel pump priming. I've checked all 3 fuse box compartments - nothing is blown. I've swapped out the fuel pump relay (found one for £1 at a local scrapyard!). I'm thinking that the ECU is probably dead, given the engine light disappeared completely.

Unfortunately, I cannot find a matching ECU with the same unit / coding part numbers. So I'm now considering sending the unit to an ECU repair company to see if they can sort it out.
If anyone is interested, the part numbers are: ECU: 37820-PVB-E51 / Coding: 742960-1517

Obviously, after I get the ECU fixed, I've got the original fault to fix too, which may or may not be the oxygen sensor. I'll get it diagnosed by a garage properly, if i'm able to get the ECU fixed. Anyway, got a couple of questions I'm hoping someone may be able to help with: :)
1. Do you guys reckon the ECU is probably the most likely fault?
2. Has anyone tried / had any luck with ECU repair companies before?

Many thanks!
 
I would not have imagined shorting a few pins would fry a board. If it has then hopefully the ECU board will have capacitors so perhaps all the repair company will do is replace that. But I would have thought a ECU from a same year and spec scrap car should work.
 
exec said:
I would not have imagined shorting a few pins would fry a board. If it has then hopefully the ECU board will have capacitors so perhaps all the repair company will do is replace that. But I would have thought a ECU from a same year and spec scrap car should work.
Not sure why you're singling out capacitors, but I agree that it would be reasonable to expect all ECU inputs/outputs to be buffered or otherwise protected... so the ECU shouldn't fry if a few pins get shorted on the OBD2 port. However, this optimism doesn't address the problem that the car is now dead, so maybe the ECU wasn't as protected as it should have been!

Is there definitely no other fuse anywhere (maybe an inline one, so not in a fuse box)?
 
They are only £20 or £30 on ebay so hopefully one of them will work.

Have you tried a battery disconnect with this one?
 
Thanks for the suggestions, much appreciated! I have tried disconnecting the battery, but no joy. I have checked the drivers side, under the glovebox, and under the bonnet fuse boxes, but haven't been able to find any inline fuse, but this would be very handy! I might have to have another look!

I've found a few Ecu's with different codings, but I'm told these would need new keys / ignition / etc too. I did get a quote from an online find-a-part website, but they were quoting £180 which seemed on the steep side. Sending it off for repair might not be a bad idea, ...unless i can haggle the £180 :)
 
If it were me, I would buy a Honda service manual on DVD for the car. Try a search on ebay.
Two years ago I bought one on ebay for my car (7th gen 2.4) for £30, it's a genuine Honda DVD, not a copy (not that it makes any difference whether it's a copy or not)
 
You used a secondhand relay? Buy a new one
 
^ Fahad makes a good point.
An extension of that point is that you could well be making the wrong ***unptions
i.e. don't ***ume that what you did on the OBD port has anything to do with the problem becoming worse than it was beforehand, it could be coincidence
i.e. the problem may have gone worse if you'd done nothing on the OBD port
 
Yep. Retrace your steps and check every fuse and relay. If the pump isn't priming, it's more likely a fuse or relay.

Sometimes it's less hassle and cost neutral to give the car to a decent electrician and let him diagnose it before replacing an ecu and finding the problem still exists
 
Yes, I'd definitely love to get hold of a manual for the the Mk6, it seems much harder than I'd thought to research online.

Yeah, admittedly, the second fuel pump relay might also be bad, given it came from a scrap yard. You're right, I do really need to find out where the problem is occurring, but it definitely seems to be an electrical fault of some kind.

The problem may have got worse if I'd done nothing with the OBD port, but the fact that the engine light went out immediately after shorting the connections (and without any other changes) does seem to be fairly incriminating. I still don't know exactly what the issue is, but I've got a phone number for a local bloke who apparently can diagnose electrical issues, so hopefully he can help isolate the cause of the fault!
 
Forget to mention - the local Honda garage/franchise in Salisbury quoted me £300 for a new fuel pump relay.... couldn't quite believe it was that much :)
 
Andy5000 said:
Forget to mention - the local Honda garage/franchise in Salisbury quoted me £300 for a new fuel pump relay.... couldn't quite believe it was that much :)
I don't think it is...that sounds like the price of a new fuel pump.
 
Manual mentioned in this link

Linas said:
here is a link for Honda ESM.no password needed.


http://downloads.hon...8-00_CD_ISO.zip
If trying to install under windows 7 check "run as administrator" and compatibility mode with XP sp3 on setup.exe file. ortherwise I believe you would not install it at all (just for win7)
wink.gif
The solder can go on the relay

https://www.youtube.com/watch?v=viIZ8k60awY


and the price is correct for the relay according to Lings


I think this it here item 22
http://www.lingshond...1&block_03=2653

B__1311.jpg


22 PFKL570005 RELAY ***Y., MAIN £370.08 (€421.89) ($614.33) 001
 
Andy5000 said:
Yes, I'd definitely love to get hold of a manual for the the Mk6, it seems much harder than I'd thought to research online.

Yeah, admittedly, the second fuel pump relay might also be bad, given it came from a scrap yard. You're right, I do really need to find out where the problem is occurring, but it definitely seems to be an electrical fault of some kind.

The problem may have got worse if I'd done nothing with the OBD port, but the fact that the engine light went out immediately after shorting the connections (and without any other changes) does seem to be fairly incriminating. I still don't know exactly what the issue is, but I've got a phone number for a local bloke who apparently can diagnose electrical issues, so hopefully he can help isolate the cause of the fault!
You can download the ESM from the interwebs there is a link for in a pinned thread in 6gen section.
 
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