Leadership Team Shortshift Posted September 15, 2023 Leadership Team Share Posted September 15, 2023 Came across MBE9A4 4Cyl COP-1342.pdf and thought it worth sharing as a diagram to complement the usual pin-out table that is often seen online for use with MBE 992/9A4 ECUs.I found this chart useful for a number of reasons, including that it helps to show a numpty like me the 'switch to earth' functionality of the ECU for injector and coil firing. Somehow, this diagram makes it all so much easier to visualise and understand.A small, additional point that I have commented on elsewhere; the diagram shows that the cam sensor return should be connected to 0V at pin #23 (which is how they are wired, ex factory) and not to pin #31 as has been mentioned previously on Blatchat.James Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted September 15, 2023 Member Share Posted September 15, 2023 MBE9A4 4Cyl COP-1342.pdf Link to comment Share on other sites More sharing options...
ChrisC Posted September 15, 2023 Share Posted September 15, 2023 Just a point, my 2020 and 2016 Duratecs had a permanent 12v supply as well as the ignition switch 12v supply. I can't be 100% certain but I think that was also the case for my 2011 Sigma. So it seems there are some inaccuracies in that diagram. Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted September 15, 2023 Author Leadership Team Share Posted September 15, 2023 Chris - it's not a Caterham-specific diagram but, as is the case with the more normally published ECU pin-out tables, it depicts a generic MBE 992/9A4 configuration (including, for instance, other features that are not normally found on a Seven, such as power shift, traction control and so on). So you may have to overlay your own individual power-supply circuitry (cut-off switch, ignition switch, starter button, etc) but as far as ECU inputs and outputs are concerned it's 100% - and complements the usual pin-out tables perfectly.JamesPS: Are you sure that your ECUs are permanently powered, even when the car is keyed-off? I'd find that rather surprising; are you sure that 'permanently powered' doesn't mean 'through the ignition switch'? Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted September 15, 2023 Share Posted September 15, 2023 Also note pins 16, 17, 19, 25, 27, 33 and 34 are all programmable, so can have any number of different functions assigned to them: Link to comment Share on other sites More sharing options...
Ian Macquarie Posted September 15, 2023 Share Posted September 15, 2023 #1 A small, additional point that I have commented on elsewhere; the diagram shows that the cam sensor return should be connected to 0V at pin #23 (which is how they are wired, ex factory) and not to pin #31 as has been mentioned previously on Blatchat."As far as I can see on that diagram MBE 9A4, CAM Inductive signal goes to pin 30 and the 0V goes to pin 5 0V. I can't see a pin 23 or pin 31 on there at all. Is there another diagram I'm not seeing? Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted September 15, 2023 Author Leadership Team Share Posted September 15, 2023 Replying to #5:Yup - and as you've mentioned before James (Aerobod), these programmable pins are features of the more recent 9Ax architectures, and are not present on the older 992 spec ECUs. Replying to #6:Yes - if you cross-refer the diagram I have posted with the pin-out table that James (Aerobod) has reposted (that's the more commonly published chart), you'll see a number of pins which offer 0V, including #5, #23 and #24.James Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted September 15, 2023 Share Posted September 15, 2023 Re #6 - Pins 5, 23 and 24 are 0V / ECU ground. Caterham uses pin 23 for Cam Return (cam signal ground), as opposed to the MBE provided Cam Return on pin 31. Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted September 15, 2023 Author Leadership Team Share Posted September 15, 2023 Ref #8:You mean: Pins 5, 23 and 24, James??James Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted September 15, 2023 Share Posted September 15, 2023 Re #9, yes, finger must have been too far to right on keyboard, will edit. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now