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

I haven't found a wiring diagram either!

I do have a parts book (pdf) that has some Wiring Harness diagrams, I determined that there were some other things that share the Earth, see a few posts further up.

If it's an Earth issue they should not be working, If they are working then it's something else and I've reached the limit of my knowledge.

It's worrying that your issue started like mine is at the moment,

I use a Torque Pro App and Dongle from Amazon and don't have a problem connecting but it didn't show any faults. Interesting that the Diagnostic port is on the same Earth

Good Luck

What an annoying problem…..

I don’t claim to know anything about GDI’s or electrickery. But would hazard a guess that with the loss of the instrumentation and with Pemlar’s OBD reader not connecting, it may be that the CAN-H and CAN-L signals from the ECU to the BCU have disappeared, or become intermittent. The connectors on the BCU might be something to check as it doesn’t take much muck or corrosion on these connector pin to lose a signal. If it was mine I might first disconnect the battery and then re-seat the BCU connectors a few times, along with a squirt of contact cleaner to clean the pins.

There’s a GDI BCU pic in this thread.

Good luck

Hi All,

A bit of an update and appeal for any other opinions.

So the issue was stable for a while, that is to say just a few short outages but...

Yesterday we had a daytrip out and on the return journey the issue came back and was much worse.

The outages were longer, maybe 30% of the journey was without them working.

This time not all the dials were affected at the same time. The Speedometer and Rev counter went and came back together but the Temp and Fuel went and came back independently.

I intend to take the dash off again to inspect and thoroughly clean every contact.

I will make a cover to protect the electrics as advised by DaveW. The car has been thoroughly soaked this year on our travels and I wondered if this has eventually had an impact, maybe even just condensation.

If the above doesn't work I'm contemplating replacing components but where to start? Cables, Dials

We have a trip round Spain booked for June next year and it would be nice to have this resolved by then.

Anyway any thoughts guys.

Regards

Double check the fuses Mark.

I had a similar problem and it turned out that the earth lead in the engine bay was the cause. The connection looked okay however it needed taking off, cleaned and fully tightened. The earth in question was behind the brake master cylinder. Best of luck.

Ken

Mark there are wiring schematics that cover all trads from 2014 to end of production within the parts book. Unfortunately they were deleted by MMC after version 6.0. This early version can be downloaded here though.

If you scroll down past actual part number listings there are many wiring diagrams and schematics. Those that cover individual elements of the Roadsters electrics can often give insight to your +4 as well, as that used a similar BCU. The +4 chassis loom schematic is probably the most helpful though with far less errors than those covering earlier Duratec cars. Individual wires within looms are not shown but each end is labelled with a unique identifier which includes it's colour(s). Also multiple connection points for sharing power/signal (bomb tails) are shown with their relative position within loom.

Hi,

Thanks All.

I'll add the Fuses and the Earth connection to the list of contacts to clean and tighten.

I traced the VDO Master Gauge connections as below. I had already traced and tightened the Earth from this cable but will do it again but also clean it.

1 = PR 6 -> Fuse Box A - No. 3
2 = B 231 -> Earth
3 = SR 111 -> Fuel System Relay
4 = UR 110 -> Wiper Relay
5 - 7 = Not Connected
8 = K 129 -> Diagnostics
9 - 15 = Not Connected
16 = KR 130 -> Illumination Potentiometer
17 = WG 53 -> Spliced with
-> WG 47 - Fuse Box A - No.10
-> WG 54 & 55 - Centre and Driver LED panels
-> WG117 - VSS SENSOR - Vehicle Speed Sensor
-> WG 118 - Illumination Potentiometer
-> WG 297 - Seat Belt Buzzer.

18 = Not Connected
19 = NW 132 -> Sliced with
-> NW 116 - VSS Sensor
-> NW 132 - Engine Pin 16 NW 32, -> ECU 86

20 -24 = Not Connected

My thoughts are that either Power or Earth is the culprit.
Power drops similar to when you start the engine.
The Earth from the VDO is to the Heater Box and I think I've read something on TM about this not being reliable and someone moved it but I can't find the thread..


Thanks again.

Not sure how the wiper relay is involved with gauges Mark. It's a standalone system so not involved with dash. UR = Blue/red wire code, generic for headlight low beam

Edit: just checked wiring schematic and that UR110 wire as well as SR111 are high speed CANBUS low and high respectively connecting to immobiliser, BCU, ECU and of course dash which would be expected to drive instruments, immobiliser warning light etc. It appears the UR wiring code has been used for alternate purpose therefore but certainly not to wiper system - thankfully.

Hi Richard, I figured out where I went wrong and confirm your findings. So for anyone reading this thread in the future here is an updated list of the VDO Master Connections.

1 = PR 6 -> Fuse Box A - No. 3
2 = B 231 -> Earth

3 = SR 111* -> Spliced with
-> SR 109 -> Engine Connector Pin 14 -> WU 65* -> ECU Pin 89 (CAN HIGH)
-> SR 113 - Diagnostics
-> SR 115 - Body Control Unit A6
-> SR 292 - Immobiliser

4 = UR 110* -> Spliced with
-> UR 108 -> Engine Connector Pin 13 -> W 67* -> ECU Pin 97 (CAN LOW)
-> UR 112 - Diagnostics
-> UR 114 - Body Control Unit A5
-> UR 291 - Immobiliser

5 - 7 = Not Connected
8 = K 129 -> Diagnostics
9 - 15 = Not Connected
16 = KR 130 -> Illumination Potentiometer

17 = WG 53 -> Spliced with
-> WG 47 - Fuse Box A - No.10
-> WG 54 & 55 - Centre and Driver LED panels
-> WG117 - VSS SENSOR - Vehicle Speed Sensor
-> WG 118 - Illumination Potentiometer
-> WG 297 - Seat Belt Buzzer.

18 = Not Connected

19 = NW 132 -> Spliced with
-> NW 116 - VSS Sensor
-> NW 132 - Engine Connector Pin 16 NW 32, -> ECU 86

20 -24 = Not Connected

Update.

Just got round to taking the Dash off.

Found it already has some aluminium covers, which saves me a job to add something.



Below is what it looks like with the covers removed, just 2 small screws each.
You can see the main cable bundle going to the speedometer (yellow connector) and then the other wires that go on to the Rev counter, temp and fuel gauges.
Dealer thought it might need a new speedometer and that it would loose the mileage if replaced, any thoughts? I thought the ECU kept the mileage and the LCD odometer just displayed it.



So far have had each dial out, cleaned the connectors and put them back in. Still got the earth points to clean before putting it all back together.

Also noticed 2x relays behind the dash, thought they were all in the fusebox, any thoughts on what they are?



Regards