456M GT Sport mode - no lamp in dashboard

I would assume that the system would illuminate a fault light if anything was wrong with the system, but perhaps your fault light is not working, too.

I can't think of any easy way of checking the light. In theory, you could short a pin to earth on the "ASR Cutoff Electronics" connector to illuminate the light. This module is on the back of the passenger footwell relay panel cover.

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i.e. short pin 3 of the wiring harness to earth (red/green wire) and turn on the ignition. Or just jumper pins 3 and 2. As a precaution, you may want to disconnect the plugs on the Bilstein Suspension Unit before you do this. However, finding the Suspension Unit is the hard part.

Does anyone know where this is supposed to be?

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Is this in the boot/trunk or perhaps in front of the driver's door?


If you were concerned about the switch itself not working, then I suppose you could swap it with another switch (e.g. window heat), but I don't know how easy it is to swap the switches. Sometimes the switch mounting plates can be quite fragile on Ferraris. You would have to push the switch out from the back... carefully.

 

Found the 456M Suspension ECU hiding under the LH Motronic ECU

https://www.ferrarichat.com/forum/threads/suspensions-ecu-location.509410/

Thanks to @456enthusiast for the photo

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The plugs on this may have small black clips saddling them which have to be pulled away from the ECU before removing the plugs.

 

Are there 3 settings for the suspension on the M?

 

I don't recall any light on the dash.. for any of the three modes on my 1995 456GT......

 

It looks like the 456M has Sport/Comfort variations similar to the F355. Some F355 switches have a shock absorber symbol, some with a shock absorber symbol and an "S", others have "SPORT". The difference between the two settings is often hard to feel. The only way you know what the light means on earlier cars is by reading the Owner's Handbook. SPORT, however, means SPORT.

Here are the switch part number variations. I don't know if there are wiring or ECU variations.

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Did this ever get resolved? Curious as I randomly have this issue all of a sudden on my 2003 GTA, It was post a lot of work including replacing the shocks, pulling the ECU’s a bunch of times, Completing a “open checkbook” major+ service, bla, bla…Several months of work with the car apart and dozens and dozens of man hours at two prominent shops back 2 back.

The switch was tested and works but no dash light, the wiring and both ECU’s seem to be ok based on the techs comments. He was dug in by the passenger seat fuse board for like an hour. The tech wanted to swap ECU’s and go from there but I had to drive 120 miles home that day. Weird. Can’t get this car right no matter what I do. Weirdly the turn signal lamp does not light up on the dash any longer either. Plus an oil leak. Christ.

 

Without "hands on", this will be impossible to diagnose. It's a complex circuit.

FWIW, the turn indication wiring and the sport wiring are completely independent (power and ground). The turn signal needs separate analysis.

Is your suspension switch labelled SPORT? Or does it have the shock absorber symbol (with or without S) on it?

Did the tech try simulating an ON signal by putting an earth on the switch connector? (on the red/green wire)?

 

The switch is labeled “sport”. I am uncertain if the tech at the second shop did that exact simulation.
More of a question along the lines of…outside of two random failures at the same time, why would these 2 particular issues present themselves immediately after $30k of work a (Major Service, electrical work, ECU work, Suspension work, you name it…) when not present prior to leaving my driveway 7 months ago. Could it be the result of something simple “missed” when putting things back “together”.

The turn signal bulb works, it just does not present a light in the cluster. same as sport mode light. All other lights work. Even the triangle suspension lamp that came on yesterday

Unlikely, but hope springs eternal.

 

All I can think of is bent pins on the instrument cluster plugs.

When you say the lamps work, do you mean the bulbs were removed and checked?

 

I'm a little confused when it comes to 456 non-M cars. According to the 456 WSM, the SPORT switch is a 3-position switch, but doesn't explain what the 3 positions do. When you say wiring to both ECUs, do you mean the Motronic ECUs? or wiring to the Suspension ECU and ?

On the 456M, the SPORT switch is attached directly to the light. The instrument panel provides power for the light and the switch provides an earth (although the earth does ultimately come from the Suspension ECU). I don't know if this is a permanent earth or whether some skulduggery is involved in the Suspension ECU

 

There is no Sport switch on the Non M cars. We have a 3 position switch for the suspension. Hard Soft and neutral, but no lights associated with them on the dash except the suspension fault light

 

So is Mirek saying he has no fault light?

 

Mirek has an M, his is 2003

 

Thanks, Nick. That makes more sense.

Mirek, are both turn signal dash lights not working?

The signals go into the dash on connector 10F /36F

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I assume you can reach under the dash and check these connections.

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Maybe when the tech was doing his wiring checks, he didn't insert the plug far enough in or bent some pins?

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Don't put the key on if you have this plug disconnected or you will set an airbag light.

 

Interesting. Yes the left lamp light comes on and is illuminating in the cabin. The right one no. Comes on. No illumination on dash. I just noticed that the fabric flap behind the wheel is not quite right so they were definitely behind the dash screwing around.

Aaaaanyway, I just noticed a small coolant leak last night and had it sent back to the original shop that did all of the work this morning. Let’s see what they say.

Seriously. A coolant leak. Looks green.
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I wonder if there is a way to verify if sport mode is actually engaging but the “sport” lamp is just not illuminating on the dash. I could live with that. My “seat of the pants meter” could not tell whilst I had it.

BTW that barnacle/wiring pic above is absolutely terrifying. All the respect in the world to you man.

 

The right turn light pin and the suspension light pin are right next to each other on the plug ... very suspicious.

What did you mean by "The right one no. Comes on. No illumination on dash"?

 

The right turn signal itself works (comes on). There is no longer an indication from inside the car on the dash.

Wow. Yep both of those interior liights are RIGHT next to each other. My fear is the shop goes on what we call “a fishing expedition” so any help i can provide.

 

I was thinking of the pins on the plug, but the lights being close to each other might also be a clue. The lights are probably mounted on a fragile circuit board.

 

Turns out it was a couple of loose bulbs. Amen, my mind went to some bad places. I am told car should be good to go this week and I am pumped. It has been a long road but back in action soon !

 

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