Can I use a ecu that has the last three digits different then the stock one.

Raia

Raia

Joined
Jan 14, 2018
Messages
181
Location
New jersey
Bike
St1300PA
My bike calls for 38770-mcs-l01 but I see sometimes a 38770-mcs- r21 or r12 for sale, will either one work?
 
Raia said:
2003
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Excuse me for not asking previously but your info says ST1300PA, PA referring to authority or police model, but Honda doesn't seem to list a 2003 PA model.

I'm trying the nail down the model designation so we can search if the ECU was superseded with a later part.
 
dduelin said:
Excuse me for not asking previously but your info says ST1300PA, PA referring to authority or police model, but Honda doesn't seem to list a 2003 PA model.

I'm trying the nail down the model designation so we can search if the ECU was superseded with a later part.
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If I remember correctly, he posted somewhere saying he picked up a 2017 ST1300P in March of this year.
 
dduelin said:
Excuse me for not asking previously but your info says ST1300PA, PA referring to authority or police model, but Honda doesn't seem to list a 2003 PA model.

I'm trying the nail down the model designation so we can search if the ECU was superseded with a later part.
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Igofar said:
If I remember correctly, he posted somewhere saying he picked up a 2017 ST1300P in March of this year.
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He also has a civilian 03. Hi guys.
 
Raia said:
My bike calls for 38770-mcs-l01 but I see sometimes a 38770-mcs- r21 or r12 for sale, will either one work?
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Generally, I would expect the answer to be no. I have observed that the last digit of a part number seems to show a small variation in the part, but smaller numbers fit and work. This may also apply to the last two digits.

But that character in front of the last 2 digits seems to represent a significant difference to the part.

38770 is used for the PGM-FI unit in many different model of Honda bike.
MCS represents the ST1300
The only thing that makes the part unique to a particular model of bike are those last 3 characters and in many cases, the letter in front of the last two digits.

eg 38770-MCS-D92 is the unit for a 2008 and later Uk ST1300
38770-MCS-G02 is the unit for a 2004 Uk model

Both are equipped with HISS. The tuning is different but the engine remains largely untouched. i would expect them to have changed the connector and wiring harness though.

---------------

eg

We have seen front brake part numbers from G01 to G04. They all physically fit and work in any pre 2008 model.
But 2008 and later models have R instead of G. eg R01, R02. R01, R02 are interchangeable, but The front brake calipers were completely redesigned and parts are not interchangeable with G01, G02 etc.

However, thats not to say that you cannot fit the complete post 2008 front brake system onto a pre 2008 bike.
The forks didnt change, so providing you don't have ABS, and the disks are the same, that may be possible. Just an example.



Comments are only from observations. The part numbers where quoted are accurate, but my decoding of them are suppositions, not known facts.
 
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jfheath said:
but my decoding of them are suppositions, not known facts.
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The below P/N decoding description is what I came across a few years back in case it adds any insight John.

The first string of digits (38770-XXX-XXX) indicates the Honda function and component number for this part. The first two digits are the function number referring to the function (sub-assembly) where the part is used. The next three numbers is the component number, the unique part that provides the function.

The second string of digits (XXXXX-MCS-XXX) is the product code, also known as Parts Classification Number (PCN) in Honda-speak. This is the number that indicates the product (car or motorcycle) where this particular part was first used. MCS refers to the Honda ST1300.

The third string of digits (XXXXX-XXX-D92) is the Modification Number.The first two digits is used to indicate various improvements for the same part. The last digit is subcontractor designation.
 
Andrew Shadow said:
The below P/N decoding description is what I came across a few years back in case it adds any insight John.

The first string of digits (38770-XXX-XXX) indicates the Honda function and component number for this part. The first two digits are the function number referring to the function (sub-assembly) where the part is used. The next three numbers is the component number, the unique part that provides the function.

The second string of digits (XXXXX-MCS-XXX) is the product code, also known as Parts Classification Number (PCN) in Honda-speak. This is the number that indicates the product (car or motorcycle) where this particular part was first used. MCS refers to the Honda ST1300.

The third string of digits (XXXXX-XXX-D92) is the Modification Number.The first two digits is used to indicate various improvements for the same part. The last digit is subcontractor designation.
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I agree with this description based on internet descriptions over the years and from the year (2018) I was ordering & inventorying parts as the parts manager in a Honda dealership. We referred to the last three characters as the vendor code. It indicated a revision so minor it did not preclude the part from being used in vehicles that originally came with the earlier part number(s).

However, regarding use of revised vendor code ECUs for the 2003 model ST1300 my research leads me to say no. The part number was never superseded by a later revised part number(s). A superseded part is no longer available after inventories are depleted and Honda begins shipping the revised part. Honda part diagrams indicate a superseded part with a solid black line through the old part number and the new part number immediately follows in red.

This image depicts two vendor code revisions that were significant enough to supersede the original part and it's first revision - #5 Drum Assembly, Gearshift p/n 24310-MGS-D20 was superseded by part revision D21 and then D21 was superseded by the D22 revision.

Screenshot 2023-05-20 at 13-08-51 2015 Honda NC700XD AC GEARSHIFT DRUM (2) CyclePartsNation.png

The 2003 ST1300 ECU p/n 38770-MGS-L01 was never revised and never superseded by the different ECUs supplied in later models.
 
On another note, I have a 2017 st1300pa ecu ends r21 2003 st ends with l01 what do you think about switching the ecu to test it ?
 
I COME AS A SPEAKER OF AUTHORITY: The L01 is the only ECU that will work on the 03/04. Only on the <2005 can you interchange the L01 or 38770-mcs-a31. The R21 is COMPLETELY DIFFERENT starting in 2008 [I have pics]/
 
aniwack said:
I COME AS A SPEAKER OF AUTHORITY: The L01 is the only ECU that will work on the 03/04. Only on the <2005 can you interchange the L01 or 38770-mcs-a31. The R21 is COMPLETELY DIFFERENT starting in 2008 [I have pics]/
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I'm confused. In the below thread you stated that the L01, R12 & R21 are all interchangeable. Is that not the case?

New to ST1300 ownership-- learning quickly about FI light and issues.... HELP! | ST1300 Related

The ECM has a voltage failure on the 25/26 port aka the knock sensors. You can replace it with any of the four ECM models or buy a new one. It's not the harness, save yourself the hassle and don't break it. 4 ECM models? Please explain!
www.st-owners.com www.st-owners.com
 
Good to know. I wasn't convinced back in 2021 but kept my mouth shut because I had never tried swapping them.

Greater numbers of people will be looking for fewer numbers of remaining ECM's. You might consider going back to that post and correcting it for the benefit of others who might find it while searching for interchangeability information.
 
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