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        General >> Problems >> Rev counter stopped working
        
(Message started by: cobrascim on Mar 14^th, 2024, 12:01pm)

Title: Rev counter stopped working
Post by cobrascim on Mar 14^th, 2024, 12:01pm

I have just replaced the screened cable between the EDIS module and PCM with a new 4c screen. Now road testing to confirm this has been an issue but after this mod my rev counter is not working. Anyone had this issue?

Title: Re: Rev counter stopped working
Post by brds on Mar 14^th, 2024, 6:40pm

Not had that issue but ref sheet 29-04-001 (Engine Control 2,9 l V6 24V EFI, Ignition) the Tachometer is driven directly from C766 pin 2 on the EDIS by a WH/BK wire to C470b Pin 32 on the instrument cluster.

Title: Re: Rev counter stopped working
Post by cobrascim on Mar 14^th, 2024, 11:06pm

The 3c shielded cable goes from EDIS straight to PCM as follows
EDIS pin wire colour PCM pin
1 white/black 49
3 white/violet 50
4 white/red 23

There is then a single wire that goes from EDIS pin 2 and it tests to pin 48 on PCM
My experience of running EDIS on my other cars fitted with megasquirt is usually that EDIS pin 2 is the diagnostic but I think I may have used it for revcounter on my other cars(long time ago and would need to check). I thought there may have been a splice in the loom to take something up to revcounter and it must be this wire as the other is a screened cable. Backed up by the fact that at the EDIS pin 2 it is a white/green wire and PCM end is another white /red. i thought about just leaving pin 2 wire and not putting it on my new 4c screened cable but put it on cable anyway. I will try and find revcounter wire and extend it round to PCM end to solder into joint.
Thanks for that info brds - makes sense and now know what I need to do. Might as well fix it now and then look into why my temp gauge goes straight to middle while I'm at it - this probably will be more damaged wires on the engine bay end of the loom going to plugs C110 and C112.
John.

Title: Re: Rev counter stopped working
Post by brds on Mar 15^th, 2024, 10:50am

You are correct about the splice. Suggest you check with diagram 29-04-001, Engine Control 2,9 l V6 24V EFI , Ignition.
All the wiring diagrams are available via the 'How to do things!' page at the bottom of the General forum.
The link is listed in the 6th item down 'WIRING DIAGRAMS'
They were very kindly put there many years ago by Snoopy.
I'm currently having to rewire the whole loom on my 2.0L 16V from the Powertrain Control Module (PCM) C402 to the engine loom C110 & gearbox loom C112. It was all in a bad way, particularly the heavy duty fan wiring that was a real fire hazard.
I did the engine & gearbox looms years ago.

Title: Re: Rev counter stopped working
Post by cobrascim on Mar 15^th, 2024, 11:19pm

Ah yes. Being the pre 95 all the colours match up to that diagram. Just couldnt initially get to the diagrams as I couldnt remember my microsoft login. Sorted now mind you.
Diagrams are the same as the scorpio wiring folder I bought off the internet last year which I hadnt looked at properly. Doh! ::)