Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing GDI Gauges Intermittent Fault

I never knew that a 2011 plus 4 ran a CANBUS system. I always thought that it only appeared with GDI models. So where is this gubbins located?

The 16 pin OBD2 diagnostics connector had pins 6 and 14 populated as early as 2007 so yes those models did use CANBUS Doug.

Hi Doug,

Anything with a MFU has a simple CAN.

IC5 is a TJA1050T

Well....

Picked up a new Speedometer Master Gauge, fitted it and tested it today with a day trip to York.

The problem occurred again so that was a waste of money, I'll now refit the original, I'm quite adept at removing the Dash now.

I'll have a good read of all the recent posts and try as much as I can while the dash is apart, but it will be a small miracle if I find the cause.

I kind of hope that it fails completely soon so that I can give it to a professional to diagnose and fix.

Regards

So sorry to read that Mark..

Hi Mark

Sorry to read the problem is ongoing, I do know that feeling. Do try the CAN BUS termination test I suggested in my post, you might get lucky.

I think there are CAN BUS data loggers that plug into the diag. socket. The principle is that the logger is fitted into the socket and left there. You continue to drive as normal and the data on the CAN BUS is logged many times per second. After a few instrument failures the logger can be removed and the data stored within it analysed. You would need a professional to be able to do this for you, I will have a look on the internet to see if I can find a company that offers this service.

One other point I would be interested to know and may help others. According to the CANcockpit manual the speedo gauge can be configured to store the odometer reading within itself or get it from the ECU. Did the odometer show the correct reading when you fitted the new speedo ?


Good Luck

Regards Tony

Hi Tony,

Have been reading through some posts and making a list of things to do/check and the termination test is on it.

I'm also waiting a call back from the dealer to discuss how we might progress.

FYI. the CANCockpit speedo read Zero when fitted.

Regards

Hi All,

Just an update on where I am, it helps to write it down, and just maybe someone will put 2&2 together and point to the issue or in a direction not thought of yet.

I set up Torque Pro dashboard on an old phone to monitor Revs, Speed, Fuel & Temp from OBD, I thought that it would be a good backup in case all failed while on tour.

I could not get Speed or Fuel!. I set up Speed from GPS as an alternative and I'd have to calculate Fuel if needed.

I found that the OBD data also fails when the Dials Fail! There are some error codes flashed up and connection to ECU mentioned.

I have checked the wiring harness diagrams and looks like the OBD is on the same CAN-BUS connection as the dials.

I checked the CAN-BUS at the VDO connector, it measured 66 ohms but I didn't manage to wiggle much while measuring, I need to buy some better probes for my multi meter to free up some hands. So this is the next thing on my to-do list.

The Speed is interesting, I found that the speed reading on the LCD does NOT fail when the dials fail, my assumption is that the LCD uses the VSS signal it gets rather than using the ECU speed, the dial may fail because it sits on the SAT-BUS with the other dials so fails when they fail.

I also confirmed that the LCD Revs fails with the dials, so does the Water Temp. There is no LCD display of the Fuel level but the DTE fails when the fuel dial does.

Although I think the CAN-BUS is the issue, I will also start disconnecting dials systematically to check it's not one of those causing the issue. My thought being that a problem on the SAT-BUS could Cause the issue on the CAN-BUS, and it won't cost anything.

3rd action I have planned is to provide a second earth point, it's another connection that is shared between OBD and VDO, even though I've cleaned and checked it multiple times, it won't cost much.

Thanks for listening

This is a tough one Mark but an observation regarding the CAN bus on my Duratec +4, that might be relevant to the GDI too.

There appears to be a couple of fundamental reliability/longevity weakness's on my Duratec. The CAN high and low signals wires exit the superbly engineered Ford ECU via gold plated environmentally sealed contacts. However.... those two wires are then each spliced somewhere in the loom most probably using a crimp joint, which is Morgan's usual technique. One wire from each of those splices then splits off to the OBD2 connector and the other more important wires connect to the MFU (an early iteration of the BCU) to process the instrumentation via what appears to be a 'cost effective' TE Multilock non environmentally sealed connector with tin/lead contacts (see the MFU image back in the thread). Please, electrical people, correct me if I'm wrong here but is this less than ideal for reliability long term?



PS -From the one image I've seen of the BCU's used in later cars, it uses the same style of connectors

Out of curiosity I just took a quick peep at the GDI electrics. So it looks like the GDI's CAN high/low signal wires enter through the 'Chassis to Engine' connector directly from the ECU (pins 13 and 14). The wires then appear to be distributed using 5 wire twisted pair splices, SP7 and SP8 (most probably located on short stubs behind the connector) with one pair of wires then running directly off to the 'VDO Master Gauge' connector.



Those splices may be weak points? I hope they have been done with more care than the regular barrel splices on the loom.
Here's a pic of an earth splice with the insulation off that fell apart and needed repair on Monty.