MBE 941 Maps needed
Discussion
Hi, I have just made up the serial lead for my MBE 941 ECU (4.2L)
as shown on MBE's website and it works a treat with the TVR diagnostics program, but not with Easy map 5.5 (Poss need ver 4 I guess or it's the USB to serial adaptor 
). Now that it works ok, I was wondering if anyone knows of any maps or has saved maps for this. Plus if anyone is interested, I have spare 1.05k & 1K resistors from farnell as specified by MBE.
Happy Burbling,
Dev.
as shown on MBE's website and it works a treat with the TVR diagnostics program, but not with Easy map 5.5 (Poss need ver 4 I guess or it's the USB to serial adaptor ). Now that it works ok, I was wondering if anyone knows of any maps or has saved maps for this. Plus if anyone is interested, I have spare 1.05k & 1K resistors from farnell as specified by MBE.Happy Burbling,
Dev.
Dev255 said:
Hi, I have just made up the serial lead for my MBE 941 ECU (4.2L) as shown on MBE's website and it works a treat with the TVR diagnostics program, but not with Easy map 5.5 (Poss need ver 4 I guess or it's the USB to serial adaptor ). Now that it works ok, I was wondering if anyone knows of any maps or has saved maps for this. Plus if anyone is interested, I have spare 1.05k & 1K resistors from farnell as specified by MBE.
Happy Burbling,
Dev.
Have a search through some old threads, but from what I recall the MBE ECU in the Cerbera has the maps locked or protected somehow. How or why I'm not sure, but there seem to be only a handful of people who have cracked it (Trackcar, Austec, TVR Power)so if you want a re-map you need to go to them. as shown on MBE's website and it works a treat with the TVR diagnostics program, but not with Easy map 5.5 (Poss need ver 4 I guess or it's the USB to serial adaptor ). Now that it works ok, I was wondering if anyone knows of any maps or has saved maps for this. Plus if anyone is interested, I have spare 1.05k & 1K resistors from farnell as specified by MBE.Happy Burbling,
Dev.
Julian64 approached MBE a few months ago to see if they would help, now that TVR are no more, but he got no help from them.
Nope MBE no help, they just shrug their shoulders. According to them the programmer that did the changes for TVR no longer works there and no information left.
Although how much of that is true and how much was just to stop me pestering them I don't know.
If you look at the map formats contained in the MBE folder you will get a general idea of where to look for the information within the 32K eprom. Although none are directly specific to the Cerb. There were some changes made but the size of formatted data is still the same which is your biggest clue.
Easimap doesn't work with the MBE as used on TVR. It will show basic fault codes but the maps it tries to show you are all over the place. Somewhere filed about two years ago I have a format that shows where most of the data is on the eprom from tiral and error, but what it was waiting for was the ability to sample or change on the fly. I was waiting for microchip to bring out a processor capable of simulating a 32K eprom in real time which they havn't quite done yet and a whole bunch of free time
Some bright spark will probably sort it for use with owners but at the mo it seems to be very expensive machinery, or simply an eprom programmer and not real time. Neither of which floats my boat.
Although how much of that is true and how much was just to stop me pestering them I don't know.
If you look at the map formats contained in the MBE folder you will get a general idea of where to look for the information within the 32K eprom. Although none are directly specific to the Cerb. There were some changes made but the size of formatted data is still the same which is your biggest clue.
Easimap doesn't work with the MBE as used on TVR. It will show basic fault codes but the maps it tries to show you are all over the place. Somewhere filed about two years ago I have a format that shows where most of the data is on the eprom from tiral and error, but what it was waiting for was the ability to sample or change on the fly. I was waiting for microchip to bring out a processor capable of simulating a 32K eprom in real time which they havn't quite done yet and a whole bunch of free time
Some bright spark will probably sort it for use with owners but at the mo it seems to be very expensive machinery, or simply an eprom programmer and not real time. Neither of which floats my boat.
Cheers for the post peeps 
, I have the 9-pin serial data connection that is located within the unit on the circuit board, I made the lead up which works fine with the TVR Diagnostic program I got with the car 
, this program allows me to change every value within the map and save it to a file and also reset the ECU if I kill it completely 
. Here is the diagram I made the lead up from: -
The only component that is hard to source from a local store is the 1.05K (1K05) resistor, plus I have increased the lead length so I can eventually fit a mini PC in the boot with a TFT VGA head up display
.
, I have the 9-pin serial data connection that is located within the unit on the circuit board, I made the lead up which works fine with the TVR Diagnostic program I got with the car , this program allows me to change every value within the map and save it to a file and also reset the ECU if I kill it completely . Here is the diagram I made the lead up from: -The only component that is hard to source from a local store is the 1.05K (1K05) resistor, plus I have increased the lead length so I can eventually fit a mini PC in the boot with a TFT VGA head up display
.
I think you can change the adaptive maps and write them back, but as these maps are dynamic (O2 sensor feedback will trim the fueling on them), they only represent a starting point.
Changing the base map seems to be the tricky thing, not sure why (does it need a read/write chip put in it?), but then I'm no expert
Changing the base map seems to be the tricky thing, not sure why (does it need a read/write chip put in it?), but then I'm no expert
Indeed, these ECU's run write only eprom's which are "burnt" in and that's it.
New map, needs a new eprom with the data loaded to it.
Only real way to do it is to have a car running M3d or the like, write your maps and then re-code to suit the MBE chip and burn those up.
If you're done that though why would you need to unless you're gonna sell the maps on...
New map, needs a new eprom with the data loaded to it.
Only real way to do it is to have a car running M3d or the like, write your maps and then re-code to suit the MBE chip and burn those up.
If you're done that though why would you need to unless you're gonna sell the maps on...
ridds said:
Indeed, these ECU's run write only eprom's which are "burnt" in and that's it.
New map, needs a new eprom with the data loaded to it.
Only real way to do it is to have a car running M3d or the like, write your maps and then re-code to suit the MBE chip and burn those up.
If you're done that though why would you need to unless you're gonna sell the maps on...
I guess 'normal' MBE ECUs have a read/write eprom? Could you not just stick one of those in an d then map away to your hearts content? New map, needs a new eprom with the data loaded to it.
Only real way to do it is to have a car running M3d or the like, write your maps and then re-code to suit the MBE chip and burn those up.
If you're done that though why would you need to unless you're gonna sell the maps on...
I realise that you'd be starting from a blank sheet, but how hard can it be?
The Cerbera ECU has several differences in how the standard MBE 941 inputs are used.
The shift light drive is on a different pin and the standard shift light pin drives one of the fans.
Oil pressure input is used as part of the inputs to control the air con.
But the main reason a standard 941 cannot be used is the ignition offset for the 75 degree V8.
The standard 941 has no configuration to handle the AJP8's physical configuration.
The shift light drive is on a different pin and the standard shift light pin drives one of the fans.
Oil pressure input is used as part of the inputs to control the air con.
But the main reason a standard 941 cannot be used is the ignition offset for the 75 degree V8.
The standard 941 has no configuration to handle the AJP8's physical configuration.
mikesr said:
The Cerbera ECU has several differences in how the standard MBE 941 inputs are used.
The shift light drive is on a different pin and the standard shift light pin drives one of the fans.
Oil pressure input is used as part of the inputs to control the air con.
But the main reason a standard 941 cannot be used is the ignition offset for the 75 degree V8.
The standard 941 has no configuration to handle the AJP8's physical configuration.
Lots then. Sounds like the TVR unit really is a bespoke system that was never intended for any sort of develpoment ability then.... boooThe shift light drive is on a different pin and the standard shift light pin drives one of the fans.
Oil pressure input is used as part of the inputs to control the air con.
But the main reason a standard 941 cannot be used is the ignition offset for the 75 degree V8.
The standard 941 has no configuration to handle the AJP8's physical configuration.
The Oil prssure line for Air Con is more than likely to allow the engine to start before the clutch engages.
AlVal said:
mikesr said:
Oil pressure input is used as part of the inputs to control the air con.
very interesting - my oil pressure gauge doesnt work, neither does my aircon!Tim
TT Tim said:
AlVal said:
mikesr said:
Oil pressure input is used as part of the inputs to control the air con.
very interesting - my oil pressure gauge doesnt work, neither does my aircon!Tim
mikesr said:
The standard 941 has no configuration to handle the AJP8's physical configuration.
Is this true for any other of the other aftermarket ECU's (motec, pectel etc.)?I know Emerald can handle the AJP, and a 'normal' V8 as well I assume (?).
Is the MBE ECU really that limited in comparision to other offerings?
BTW does anyone know the spec of it (processor, speed etc..)? It must be pretty outdated by now.
The oil pressure in put on the ECU is used as the air con request line. Its not actually reading the oil pressure. Just a voltage from the air con control box.
The air con acknowledge is the inter cooler spray pin on the ecu.
I suspect that the cerbera unit is so old that what is now the oil pressure pin on 941s never actually was on the early cerberas.
They probably just used a spare pin.
The myth is that the air con would be turned off under particular conditions - when rpm exceeded some value. Hence the a/c request to the ecu and an acknowledge that goes back to the heater/aircon control box. I posted an aircon diagnosis way back when (and have linked to it on other posts about air con). It describes all the detail of the wiring in and out of the ecu.
Trackcar and I never got the aircon to switch off. So maybe it is just a myth.
The internals are very old. The processor is a 8XC196KB or variant thereof in later cars. The early ones had no onboard prom which is how I knew there was no code locked away in the processor.
The EPROM is a M27C256B-12F6 device
The NVRAM is a DS1230AB-100 device
The air con acknowledge is the inter cooler spray pin on the ecu.
I suspect that the cerbera unit is so old that what is now the oil pressure pin on 941s never actually was on the early cerberas.
They probably just used a spare pin.
The myth is that the air con would be turned off under particular conditions - when rpm exceeded some value. Hence the a/c request to the ecu and an acknowledge that goes back to the heater/aircon control box. I posted an aircon diagnosis way back when (and have linked to it on other posts about air con). It describes all the detail of the wiring in and out of the ecu.
Trackcar and I never got the aircon to switch off. So maybe it is just a myth.
The internals are very old. The processor is a 8XC196KB or variant thereof in later cars. The early ones had no onboard prom which is how I knew there was no code locked away in the processor.
The EPROM is a M27C256B-12F6 device
The NVRAM is a DS1230AB-100 device
Thats interesting, cos when I did the circuit diagram for mine, the configuration setup was for the eprom to contain the program.
But when I used a dissassembler on it I got complete nonsense. No code at even the reset point.
I therefore stopped at that point as the code was obviously within the locked processor prom, and the eprom and NV were being used as purely data, or so I thought at the time.
Are you telling me all this time you've actually got a dissassembly of the processor code and you've been sitting on it.
If so could you please pull your finger out and organise the code to work with the easimap software, or at the very least distribute the code for us all to work on the logical next step .
(Sorry does that sound pushy. If it does that's because you've been sitting on some of the best info on the Cerb since someone posted the Cerb manual on Cd.)
But when I used a dissassembler on it I got complete nonsense. No code at even the reset point.
I therefore stopped at that point as the code was obviously within the locked processor prom, and the eprom and NV were being used as purely data, or so I thought at the time.
Are you telling me all this time you've actually got a dissassembly of the processor code and you've been sitting on it
.If so could you please pull your finger out and organise the code to work with the easimap software
, or at the very least distribute the code for us all to work on the logical next step .(Sorry does that sound pushy. If it does that's because you've been sitting on some of the best info on the Cerb since someone posted the Cerb manual on Cd.
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