At some point in the past I have been playing with my Accord’ ECU (yes, bad idea) and ended up damaging the rewrite pin logic with my super-cheap-skates solder iron which most likely has leaking neutral or even live. Anyway, I was on hunt for another ECU..
Naturally, off to eBay and typed in my ECU PN and few results came up. Though I was expecting many more. The one that matched my ECU was quite expensive, circa 100 quid, which for 16 year old car is expensive in my opinion. So I tried searching MPN instead (manufacturer’s part number) which in this case is made by Bosch.
I then found some listings that had same MPN but different Honda PN. That got me thinking if supplier provides unit under same MPN, why Honda issued different PN? Only one answer came to my head – revision control.
This means, they have made some functional changes that worked with the same hardware, in other words, it was a software update.
Right, here comes the best part of it – there’s more of the ‘revised’ PN ECUs and they are cheaper.. Yay!
An picture for information, the 37820-RL0-G03 is PN and 0 281 014 809 is Honda PN.
I then carried on with a little research where I found some really good websites, writing about this sort of stuff.
I have added links at the end of this post but in case the website goes down, here’s the actual data:
Honda ECU Part Numbers Decoded
Honda ECU part numbers are a series of 3 alphanumeric sections.
FORMAT: xxxxx-xxx-xxx
- The first block is the Honda part number denoting it is an ECU. This is almost always 37820.
- The middle 3 digits are the main identifier of the ECU and used in the table above, first column, ECU Code. This code is often associated with the engine or car. for example, a PR3 ECU often has an engine with a PR3 headstamp.
- The Last 3 characters denote the ECU Revision type and each character is a different indicator.
- The first character indicates market the ECU is intended to support.
- A – USA
- C – Canada
- G – Europe
- J – Japan
- The second digit denotes transmission type
- 0 – Manual
- 5,7,9 – Automatic
- The last character indicates the version number and generally does not have any significant changes to connectivity or function. Additional revisions may exist on the ROM inside, which will be indicated on the chip itself.
How to tell if your Honda ECU is Automatic or Manual
You can tell the type of transmission the ECU is designed to control by the trailing 3-digits in the full model code.
As you saw above the 2nd character in the final 3 of the part number indicates the transmission type. Look for the 0 in that position for manual.
OBD0 ECUs
(eg, PM6, PR4, PW0, PR3, PM7):
Manual = 000, 001, 002, A00, A01, A10, J00, J001, C01, C00
Auto = J51, J50, A50, A51, 900, 901, A60, C50, C51, X30, A80OBD1 ECUs
(eg, P28, P30, P61, P72, P91, P08)
Manual = 000, 001, 002, 003, A00, A01, A02, C00, C01, C02, J00, J01, J02
Auto = J50, J51, 900, 901, 902, C50, C51, C52, A50, A51, A52OBD2 ECUs
(eg, P2E, P2P, P2J, P72)
Manual = 000, 001, 002, 003, A00, A01, A03, C00, C01, C02, C03, J00, J01, J02, A11, C11
Auto = A70, A71, A72, A91, A92, C70, C71, C72, C91, C92Locating the ECU
The ECU is generally located in the passenger compartment instead of the engine bay. This helps keep it clean and dry and away from extreme temperatures. It is a computer, after all.
- OBD0 cars – usually located under a metal plate in the passenger seat footwell
- OBD1 cars – usually located under the carpet in the passenger seat footwell (on the right side)
- OBD2 cars – usually located behind a plastic panel in the passenger seat footwell
Source: Honda ECU List | HondaSwap.com
Have a browse in this forum, there’s plenty of great information – will easily kill hours of your time 🙂
So the plan is, as soon as second hand ECU arrives to flash it with my own software and see whether it works as it should, will post the outcome in the future.
Enjoy and till next post!
P.s. the pictures are not mine – I borrowed them from the page 37820-RL0-G03 0281014809 COMPUTER CONTROL UNIT ENGINE HONDA ACCORD 8 2.2 I-DTEC 37820-RL0-G03 (recambiopl.com)