Help! I am an idiot : Ecu / multiplex

[NSX_Wannabe]

Guys

I am in a state of severe distress! I mothballed my NSX during the crap weather in Nov / Dec....but the battery ran down. I turned the battery around on the plate (to access the terminals) and connected a trickle charger. 3 weeks later I returned and connected up the battery but forgot to turn it around thus connecting up the wrong terminals!

There were sparks and something started to whirr..I disconnected immediately. I blew the large battery fuse and another minor one.

However, the engine would not fire. It turns over ok and all the dashboard lights are on.

I took it to the local garage who have assessed that the Engine ECU (part no. 37830PBYG51) and TCS Multiplex (part no. 39900SL0043) have either gone to sleep or are fried.

I need to get the two units tested but the garage can't find anyone to do it...

This idiot needs help - any ideas?

Justin

[forumadmin]

Kaz has a spare ECU that belongs to Silver Surfer.

I'm sure it will be for sale.

[Sudesh]

Year and model of your car will help, as they differ between auto/manual and year.

If they are fried I hope you can find them used as one unit is over £3k from Honda, the other close to £1k

I might have both but need to check part numbers.


Guys

I am in a state of severe distress! I mothballed my NSX during the crap weather in Nov / Dec....but the battery ran down. I turned the battery around on the plate (to access the terminals) and connected a trickle charger. 3 weeks later I returned and connected up the battery but forgot to turn it around thus connecting up the wrong terminals!

There were sparks and something started to whirr..I disconnected immediately. I blew the large battery fuse and another minor one.

However, the engine would not fire. It turns over ok and all the dashboard lights are on.

I took it to the local garage who have assessed that the Engine ECU (part no. 37830PBYG51) and TCS Multiplex (part no. 39900SL0043) have either gone to sleep or are fried.

I need to get the two units tested but the garage can't find anyone to do it...

This idiot needs help - any ideas?

Justin

[Senninha]

Oops!

If you are not an immediate hurry then Kaz should be able to test and maybe repair depending on damage done.

Post the question in his health check thread. He is very busy but will offer advise in the meantime.

Hopefully you haven't done too much damage.

The dash lights and engine spinning without firing sounds like the common(ish) main relay fault so you may 'only' have damaged this part.

Good luck

Paul

[AR]

Where are you located?

I have a spare TCS ECU from a 1993 car.

[duncan]

Try a post on Prime, you won't be the first and you won't be the last. With the greatest number of cars in the US, the chance for others will be the greatest.

In arriving at their solution how did your garage diagnose the problem? Ask them which fault codes were recovered, each check light has the ability to display its own faults.

As a speculation, with so many relays and with so many of those having diodes in line with the solenoid coils it may be that the power didn't get as far as you fear.

Don't panic yet.

[WhyOne?]

If it is the main relay which has gone, and yours is a DBW car, I have a working spare you are welcome to borrow, just shout.

[NSX_Wannabe]

Firstly, many thanks for all the offers for help...

The garage I am using is not a specialist...but one of their mechanics used to work for Honda and has NSX experience.

They do not have specialist equipment but their disgnostics have determined that power is going to the ECU and TCS but nothing is coming out.

Their suggested approach was to send the 2 units for testing to evaluate if they are fried or not, but they have had a ring around and none of the companies they use have the expertise / equipment.

Given the suggestions posted my intended approach is:

Ask the garage which fault codes were detected (thanks Duncan) - who would be able to decipher them?

If no luck here get in touch with Kaz and see if he can test the units.

If I need to buy the replacements , I will definitely be in touch!

Does this make sense?

The car is a 1991 3.2 pop up & I live in Cranbrook, Kent

Thanks again

Justin

[Senninha]

.....The car is a 1991 3.2 pop up ....

Thanks again

Justin

I'm guessing there is a typo in here somewhere ;)

[NSX_Wannabe]

Sorry 2001....

[amo]

so you will be needing a na2 ecu as the na1 will not be the same.

thx amo

[Silver Surfer]

NA2 ECU for sale...just advertised on Prime!
http://www.nsxprime.com/forums/showthread.php?t=133843

SS

[Sudesh]

So its a 2001 3.2 Manual or Auto?

As mentioned ECU and TCS will differ between years and type.

Couldnt find the part no. 37830PBYG51 that you mentioned?

[NSX_Wannabe]

It's a manual

[NSX_Wannabe]

and (another) typo...

Part no. is 37820PBYG51

[duncan]

..."Ask the garage which fault codes were detected (thanks Duncan) - who would be able to decipher them?"....
Your garage,....you,...us,....
....go to the Prime site, go to Forums, go to Wiki and look at the thread called Service Manuals.
As a 2001 car your car will be OBD11, use the 97-05 link.
My understanding is that the OBD11 cars have both a diagnostic port and retain the earlier test link.
Your garage should have knowledge of OBD11 codes, the codes are universal, if not a question on Prime should give an answer once the code is retrieved.
If you use the test link by using a jumper [bent paper clip] the dash warning light[s] with stored error[s] will flash like morse code; dots and dashes. If you don't get the reading first time, switch off and switch on and re-read. The earlier, non electronic, scanned copy of the factory service will walk you the range of options with each error code.

[NSXGB]

Duncan is right, you will have an OBD11 port.
For anyone interested, the autodata software has the NSX codes and other useful data in it's database. You'll just have to find a copy somewhere....

[NSX_Wannabe]

Duncan

Thanks for this

I think I found the relevant Service Manual pages on the Prime site and have forwarded them to the garage.

Also have contacted Kaz via email.

Fingers crossed they can decipher what is wrong.

Justin

[NSX_Wannabe]

No luck yet...

The mechanic reckons he needs a SCS Service Connector (07PAZ-0010100) to get the dash to blink at him and give the fault code...

Is he right?

If so - does anyone have an idea as to where I can get one? I got a stoney silence when I spoke to the parts guy at Honda Maidstone...

The ECU doesn't appear to be fried (ie the garage is getting some readings via the OBD11) - but the rest is either damaged or asleep.

Thanks again for the help, without your input I would be squarely back at stage 1.

Justin

[Silver Surfer]

All you need is a paperclip!

SS

[NSXGB]

As SS points out a paperclip is all that's required to bridge the service connector under the glove box. When this is done and the ignition is turned certain dash lights (corresponding to where the fault lies - ABS, ECL, etc) will blink in it's own special morse code. You then look up the code on the NSX Prime wiki to decode.

In short (excuse the pun) you only need the paperclip to bridge the service connector to make the dash lights blink.

Here you go:

http://www.nsxprime.com/wiki/Trouble_Codes

Don't understand when he says that the reset is either asleep or damaged as just disconnecting the ECU will reset it.

[NSX_Wannabe]

Thanks guys

Have forwarded the link to the garage - so we'll wait and see what is detected...

Justin