Problem still exists!!

[TrevorB]

Hi Simon, thanks for your response.

That's interesting - The VSS and the CEL share the same ignition feed but have different grounds. Does the CEL light when you turn the ignition key?

The CEL light does not come on when ignition turned on. I did wonder why this had stopped happening.
I need to resolve this and this is presumably an earthing issue?

Are the ground for the coil pack and the plenum properly secured?

I can check the coil pack ground, but where is the plenum ground?

Cheers

Trevor

on the drivers side end of the plenum - right by where it meets the intake manifold 0r on the intake manifold 4 black wires.

Think I've found that ground and it does appear to be secure. I did want to release it and clean it up but haven't a narrow enough ratchet or long enough spanner of that size to get into the gap!

Creating a file from Elanscan
File - Save as
Save in – Desktop (or wherever you choose)
File name: Merlot ddmmyy run1 etc
Locate file in on desktop, zip it, post it on LEC

the file doesn't exist until you have saved it.

Unfortunately I am unable to run elanscan as it doesn't work with Windows 11 and RonR has borrowed my cable anyway. There is another thread that is discussing this issue.

[Simon_P]

or the bulb - it is always worth checking earth wiring and connections, but they appear to be separate the common feed is on the + side from the ignition switch. Anyway, it tells you all of the connections so you know where to check and clean contacts.

CEL VSS wiring.JPG

page 65 of electrical manual. 24 refers to sheet 24 which un turn refers to sheet 28.

Unfortunately I am unable to run elanscan as it doesn't work with Windows 11 and RonR has borrowed my cable anyway. There is another thread that is discussing this issue.

buy a 20 quid laptop and borrow your cable back

Think I've found that ground and it does appear to be secure. I did want to release it and clean it up but haven't a narrow enough ratchet or long enough spanner of that size to get into the gap!

there are 2 separate terminals it is really easy for one to slip out of the way when you do the screw up - check that there isn't a ;oose wire with the arm up a cow's bum method where you should be able to put your hand on them.

[RonR]

Hi Trevor,

Did you ever try a different instrument cluster in Merlot?

The VSS connects to the car via a flexible circuit board attached to the back of the cluster and is clipped in place, then the signal goes through another flexible connection into the loom.
The copper tracks on these can harden and crack over time (ask Joao!).
That would be my next port of call.

Here's my spare - Red arrow is VSS connection, Blue arrow is connection to loom:

Flexi-sm.jpg

Oh yes - I need to give your Elanscan cable back!

[dapinky]

Hi Trevor,
Did you ever try a different instrument cluster in Merlot?

I did lend Trevor my spare instrument panel at CC last year.... didn't have time/opportunity to fit it to try, but he has the parts.....

[TrevorB]

I did lend Trevor my spare instrument panel at CC last year.... didn't have time/opportunity to fit it to try, but he has the parts.....

Yes, I still have that and was looking at it only the other day to identify the access to the lamps.
I wouldn't know where to start in respect of changing it.
But RonR has contacted me and has offered to come over to investigate the electrical problems currently being experienced which are in addition to the VSS issue. Ironically though there could be some correlation.



Trevor

[RonR]

Been doing a bit of prep work for Merlot's check-up but couldn't find any info on the flexible boards or connectors.
I've annotated some photos so we know where we are:

Flexi-trace-sm-comp.jpg

Flexi2-trace-sm-comp.jpg

For reference I've included some bulbs which are not used in the M100, and I haven't bothered with the very bottom row as it isn't even visible when the cluster's in place.

Also for Reference - the VSS feed connects to ECU pin A10:

ECM Pin Labels.jpg

[TrevorB]

I took the binnacle cover off today and just checked that the VSS and loom connections were ok and also checked other connections the best I could. I then went out for a drive and everything was fine with no VSS issue.

Can you understand why it's such a frustrating fault?!

Also to add, the only indication on dash when ignition turned on is the oil light.

RonR are you ok to come over Monday? txt me confirmation.



Trevor

[Tuga2112]

add, the only indication on dash when ignition turned on is the oil light.

the alternator light should have been on if the engine is not running as well as the CEL light. ~~
af far as the instrument cluster traces, the one that broke in my case made both alternator light as well as the tacho not read the RPM but depending on where the damage is you can see different problems.

nothing that a continuity check wont confirm for sure

[RonR]

A plan of action is forming:

I'll try to do the cow's bum thing whilst holding a mobile phone to see if there's a broken earth wire at the back of the plenum.
Things to check on the instrument cluster:

Bulbs - including CEL
The 0 ohm resistor underneath the speedo, it supplies 12V to the VSS and BATT light, and we know the supply is reaching one end of it as the Oil light's working.
Flexible VSS connector, trace continuity and retaining clip
Continuity between VSS terminals and: Gnd, +12V IGN and ECU pin A10.
Jack up and spin a wheel to see if VSS pulses are reaching the ECU properly.

All other ideas gratefully received...

[RonR]

Here's what we found during Merlot's check-up today:

1. Gnd connections on Plenum all OK, tested back to instrument cluster and VSS.
2. 5 Ohms resistance between VSS and ECU Pin A10.
3. Just the Oil light comes on when IGN turned on.

We decided to remove the instrument cluster to see if we could find the problem.

Someone had been there before.....

Main harness connections.jpg

Second harness connections.jpg

Burnt track.jpg

soldered in BATT lamp.jpg

bodge 1+2.jpg

We tested all bulbs - when it was discovered that the BATT bulb was soldered in, probably as part of the previous bodge / repair, and many bulbs were blown in both clusters.
The track to the High Beam light (just under the BATT lamp) looked decidedly iffy.
The two repairs had been made to tracks which were used by the VSS and the right hand bank of tell-tale lights.
So after inspecting Pinky's spare cluster which had a much better flexible pcb we decided to make a good cluster from the two.
Merlot's instruments were duly swapped into the spare's casing and all tracks and bulbs were then tested. All good so far.
The rebuilt cluster was then re-installed and with fingers crossed Trevor turned the key.
I'll let him describe what happened next...

We didn't have time to go for a test drive so the VSS problem could still rear it's head again, time will tell I suppose!

As an afterthought we tried Trevor's returned Elanscan cable with his Windows 11 Laptop and the driver settings which worked on my Windows 10 machine - and It Worked!!!
Elanscan still dropped the occasional data record but there was enough data coming through to be usable.

[TrevorB]

let there be light!

More to the point LIGHTS. Lots of them it was like Blackpool illuminations on the dashboard.

Ron has performed a miracle to get everything working again. It's amazing 'Merlot' was going at all. As Ron has said we run out of time so I'm still to give the car a proper run out.

Dave Pinky we've had to use your cluster to get to this stage so let me know how I can make up for it. I can purchase the small and main circuit boards from sjs which will help getting the original cluster back to some normality.

Finally, a huge THANK YOU to RonR .



Trevor

[dapinky]

Trevor, it would be far more cost effective to get an Astra J Diesel cluster for the parts..... it is the same unit as used in the M100, but with a different front perspex bit (and different colour faces, different gearing for odometer.... but most parts are identical.

I will go into the loft this week to see what condition the flexible bits on my old Astra part are like.... I bought it many years ago for spares!

[dapinky]

Trevor, it would be far more cost effective to get an Astra J Diesel cluster for the parts..... it is the same unit as used in the M100, but with a different front perspex bit (and different colour faces, different gearing for odometer.... but most parts are identical.

I will go into the loft this week to see what condition the flexible bits on my old Astra part are like.... I bought it many years ago for spares!

[Tuga2112]

its worth noting that those PCB traces can be repaired to a (IMO) perfectly adequate standard with simple stuff from ebay.

its good to know that a real problem was now diagnosed and addressed, fingers crossed you will be running 100% going forward.

when you said 2 of the 3 lights were not working with the ignition on, my mind raced to PCB traces being broken. (reason for my previous comment) but seemed unlikely as the only reason mine broke was that i faffed about there with the LED bulbs replacement.

now go out there and get a bunch other youtubers to test drive your car and make wonderful reviews..

[Simon_P]

More to the point LIGHTS

that sounds like a productive session gents! I wonder how it all got burnt in the first place?

2. 5 Ohms resistance between VSS and ECU Pin A10.

With the ground ok and a new Vss that's worth further investigation.

I've been a bit distracted, I meant to suggest and set of spare bulbs - looks like you've covered that. Also looking through Trevor's post history there's a photo of a new boost control valve and under it two crimped splices probably nothing...

[TrevorB]

Finally managed to get a photo of dashboard to size that would download.

Now that's how it should look.

PSX_20240312_105757.jpg

[Tuga2112]

this is a VERY bad sign for me...

[RonR]

I wonder how it all got burnt in the first place?

We found a scotchlok-ed extra few wires and an in-line 5A fuse behind the dash - I think it may have been when this was being installed that the damage was done. I didn't investigate further, but the wires were connected at one end to Red and the other to Red/White. Could also have been the after-market alarm installation.

With the ground ok and a new Vss that's worth further investigation.

I tested the VSS to ECU connection after changing the cluster and it was down to <1Ohm, so fingers crossed and we'll see if the fault returns.

Also looking through Trevor's post history there's a photo of a new boost control valve and under it two crimped splices probably nothing...

Didn't notice that one! Another avenue to investigate if the problem returns!

Many of the instrument illumination bulbs were blown, and as we didn't have spare 2W bulbs they were replaced with 1.2W versions.

Q. about the VSS: As it's an optical sensor I'd expect it to have it's own light source, hopefully it wouldn't rely on instrument illumination would it?

[Simon_P]

down to <1Ohm,

that'll do!

Q. about the VSS: As it's an optical sensor I'd expect it to have it's own light source, hopefully it wouldn't rely on instrument illumination would it?

should do - SE dash illumination usually off, and all can be turned off with rheostat.

[TrevorB]

After two exhilarating and enthusiastic drives, yesterday and today, to do a final test to see if the VSS code 24 fault has been fixed
I am extremely pleased and relieved to report that there has been no issues. The drives included plenty of high powered drives through
the gears with revs up to 8000rpm so a good test of turbo and engine. I was going to connect the laptop and Elanscan but the excitement
of getting the car out overtook that.

I have to THANK RonR once again for the work he has done to get this fault finally fixed.

Also, Dave Pink for the donor instrument cluster that was used in conjunction with original from the car to produce a working one.

RonR has taken the original cluster away and is hopefully going to get that in working order so that Pinky gets his instrument cluster back.

I would also like to thank ALL the members that have contributed to this post.

Finally, lets hope this fault has produced some ideas when you get that annoying electrical problem. Although I think RonR and I don't wish it
on anyone to have to remove the instrument panel.

Take care everyone.



Trevor