MBE Data cable woes

[Griffith500user]

Related to my 'First Engine Start' post, a bit more investigation into the reported 20v battery voltage and extremely high oil pressure on crank, I found that at the same time, the dashboard was reporting sensible data, 12.3v battery voltage and oil pressure in the 10's. Glancing back over at the laptop it would appear that the battery voltage was showing 20v, oil pressure 151psi and both temps had gone from reading a sensible 12deg prior to crank, up to 130deg when cranking. And indeed all channels on the laptop froze at these wild figures during cranking.

Which leads me to believe that maybe I have a comms issue from the ECU to laptop? I bought the correct serial to serial lead, my car being the early type MBE ECU with the internal serial port. Realising my laptop didn't have a serial connector, I bought an RS232 to 9 pin serial adapter to allow connection to USB on my laptop. I'm now wondering whether this adapter is causing the issue?

I guess trying to locate a laptop which runs Windows 10 or newer with integral serial port is my next step?

Does anyone have experience of anything similar?

[notaping]

First place to check is the serial lead. Did you buy a standard serial lead , or the specific MBE lead. You need one that is wired like this :

[Basil Brush]

How early is your car? Mine is July '00 but still has the 3 pin diagnostics lead.

[Griffith500user]

Mine is a '2000 car, I'll check to see if the 3pin connector is there or not, but having seen it had a serial connector inside the ECU I didn't look any further.

I bought the serial to serial data lead from Motaclan so assuming its wired correctly. Would the serial to USB adapter I bought from Amazon have any relevance to this though?

[Basil Brush]

I guess you're nowhere near Leeds, otherwise you could borrow my XP laptop with serial port?

[notaping]

Griffith500user said:

Would the serial to USB adapter I bought from Amazon have any relevance to this though?

Could do. From memory, I believe some people had problems depending on the chip used in the adapter. I use this one. . .

https://www.usconverters.com/usb-serial-adapter-xs...

but anything with a FTDI chip should work

[Griffith500user]

Basil Brush said:

I guess you're nowhere near Leeds, otherwise you could borrow my XP laptop with serial port?

Salisbury, but thanks anyway. I do have an old Panasonic Toughbook which runs XP and has a serial port. The issue is trying to get the software on there as I'm not sure the wifi connection works. Might be my next port of call

[Basil Brush]

Griffith500user said:

Basil Brush said:

I guess you're nowhere near Leeds, otherwise you could borrow my XP laptop with serial port?

Salisbury, but thanks anyway. I do have an old Panasonic Toughbook which runs XP and has a serial port. The issue is trying to get the software on there as I'm not sure the wifi connection works. Might be my next port of call

I had to use a usb drive to load it as software too out of date to connect.

[Griffith500user]

To add closure here, I found that the combination of laptop and USB to serial adapter with the Motaclan supplied serial to serial data lead was the issue.

Just so happens I found an old Panasonic Toughbook that was running Windows XP, managed to install the MBE Tool software onto it and eliminated the USB to serial adapter as the Toughbook had its own serial port. This combination fixed both the high battery voltage and oil pressure readings and stopped the live data freezing during cranking.