Still havein reverse problems
- Thread starter Steve GS
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mjheathcote
Centenary Club
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Thats a very kind offer, if only I was nearer it would be interesting to see the data available.
Steve GS
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Will pm you if I can make it down this day thank you. Happy Christmas to you.
voicey
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So Steve dropped by today. The first thing I did was to check to see if the clutch was dragging on the flywheel as this is a common issue when having reverse selection problems. I can check this by monitoring the speed of the gearbox input shaft with the engine running and the box in neutral. There should be no movement of the input shaft - if there is then the TCU thinks the car is moving forward and will not select reverse. This was not the case for Steve.
So the next thing we checked was to see if there was a mechanical problem stopping reverse being engaged. I used to my diag tool to force the TCU to select reverse - it did this with ease, several times.
Finally I used the diag tool to monitor the requested gear status. When Steve used the paddle to request first gear I would see this on the diag and then I'd see that the gearbox was in first. When he selected neutral the same occurred. When Steve pulled the reverse lever the TCU didn't receive the signal so nothing happened. The same occurred when he pushed the lever forward to select first (ie: nothing).
The final clue was when I scanned the TCU for errors - it was showing P1747 which is "REVERSE GEAR SWITCH". My Ferrari workshop manual gives the following guidance for this error: "Defect found on the dashboard reverse switch. Switch status inconsistent with the levers' conditions of use".
My conclusion is that there is a problem with either the switch or the wiring between the switch and the TCU.
So the next thing we checked was to see if there was a mechanical problem stopping reverse being engaged. I used to my diag tool to force the TCU to select reverse - it did this with ease, several times.
Finally I used the diag tool to monitor the requested gear status. When Steve used the paddle to request first gear I would see this on the diag and then I'd see that the gearbox was in first. When he selected neutral the same occurred. When Steve pulled the reverse lever the TCU didn't receive the signal so nothing happened. The same occurred when he pushed the lever forward to select first (ie: nothing).
The final clue was when I scanned the TCU for errors - it was showing P1747 which is "REVERSE GEAR SWITCH". My Ferrari workshop manual gives the following guidance for this error: "Defect found on the dashboard reverse switch. Switch status inconsistent with the levers' conditions of use".
My conclusion is that there is a problem with either the switch or the wiring between the switch and the TCU.
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Good detective work, voicey. So fingers crossed it should be a relatively quick and cheap fix... assuming the switch / wiring is fairly accessible and any parts prices are not taking the proverbial. I look forward to a happy conclusion.
Incidentally, is your 430 Grigio Silverstone? It looks fantastic in that colour, whatever it is.
Incidentally, is your 430 Grigio Silverstone? It looks fantastic in that colour, whatever it is.
Steve GS
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What a great man voicey is taking time out for me. But the plot thickens as driving home I had to mount a kerb (slowly) not knowing if this had anything to do with things but when I parked up the switch selected reverse. So could there be something lose underneath.
voicey
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It's really odd that it would start working again. Steve - was that the first time you tried it from when you left mine? I did do a gearbox relearn but as a courtesy not because I thought it would fix it. Maybe that changed things.
I would still bet on a wiring issue though - does anyone have a wiring diagram for these cars? I'd like to check what signal the TCU is supposed to receive from the lever. From there is should be fairly simple to check the wiring.
PS: Yes, F430 is Grigio Silverstone - thanks for the kind comments!
I would still bet on a wiring issue though - does anyone have a wiring diagram for these cars? I'd like to check what signal the TCU is supposed to receive from the lever. From there is should be fairly simple to check the wiring.
PS: Yes, F430 is Grigio Silverstone - thanks for the kind comments!
Steve GS
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I tried it at every set of lights on the way home and nothing. Until I bumbed up the kerb then down. It's stopped working again now. What I did notice is when it was working the battery meter was reading lower than when it wasn't working.
Maybe thats the problem with mine. My car is a weekend drive, but if I don't drive it every week, it needs a jumpstart. Believe this is down to an issue with my nearside window not lowering when I open the handle.
Anyhow, I also have the reverse gear issue, but it seems to sometimes intermittent. Had taken it to Autoficinia in Chessington who said it may have been an air bubble in the system, so drained it all out. Didn't solve the problem (did lighten the wallet though), but the boss there didn't think it was an issue and suggested I just wasn't giving it enough time when I held it down. Eventually said I'd probably need a new clutch soon if it continues. (Their reading shows 78% wear?!?)
Hadn't thought it could be related to the battery before.
Steve GS
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You never know it could be battery related
On voicey diag kit mine was showing 60% clutch wear and all the gears are working fine including reverse its just the switch not selecting it I'm presuming its a wiring fault one way for me to test this is try my switch in another car
(any offers).
On voicey diag kit mine was showing 60% clutch wear and all the gears are working fine including reverse its just the switch not selecting it I'm presuming its a wiring fault one way for me to test this is try my switch in another car
(any offers).
Steve GS
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If the same problem as mine it's not the clutch as this is working as it should. There is another issue here.
I suppose I should get the battery issue resolved and see if that solves it really. Will try and get it booked in at the mechanics and see if the window issue can be sorts it out. Will keep you posted.
You're welcome to try your switch in my car if you know what you are doing.