355 F1 gearbox warning light

My '99 355F1 decided to complain yesterday.

I set off for home and as I reached 2nd, the red dashboard gearbox warning light lit up, and there were warning beeps issued. The car would not get past 2nd, even when in Auto mode.

However if I put the car in neutral and then re-engaged the F1 (by pushing up paddle) it would rejoin in 4th or 5th. The gearbox would work its way down to 1st, but would at no point change up beyond 2nd.

We checked a few things, but I'm at a loss TBH. The F1 gearbox oil level looked very low, but when we let the car sit for a while it had settled and the dipstick showed the correct level.

It reminds me far too much of when I first got the car in '00 and it had a broken motor mount which kept causing the engine computer to become disconnected. It once switched the motor off while I was driving.

At some point the amber suspension warning light also came on (and remained on)

I carefully drove home and I noticed that the speedo wasn't working and the trip meter didn't change. So our conclusion is that a cable or connection has become disconnected. When parked in the garage I saw it reach 40mph while in reverse (I was stationary, the speed just read 40mph - my garage isn't that big!)

Any thoughts as to the cause and where to start looking? I don't have lifts or ramps though, so not sure how much I can do myself.

Just shipped from USA to UK, but I've been on a couple of nice rides since the major work was done.

However the gearbox display LED was replaced by the local dealer recently, and the dash head appears to be quite loose (according to my cousin )

Thanks!
Richard

 

If the car is parked, and the engine running, the car will not shift past second gear.

If you just turn on the key and do not start the car, you can select all the gears.

If the speedo is not working, it may be the speed sensor on the tranny. The F1 ECU needs that input to compute shifting. Might be worth a look.

Historically, worn motor mounts can cause the actuator shaft to hit the rear cross member giving all sorts of fits in shifting...another one to look at.

 

I'm not having any issues but I appreciate this post since it has lot's of good info.

 

Thanks!

Yup - I had to explain the 1st & 2nd while engine on to my cuz (for better traction you might want to take off in 2nd)

We were able to select all the gears with the engine off.

Thos are two great thoughts as to the problem. The motor mount, since I've encountered it before, is a concern. It really has massive issues when trying to stay in 2nd at times, feels like a kangaroo is kicking you. Which sadly is incredibly reminiscent of when I had the broken motor mount (although some of the symptoms this time are slightly different - I never got any warning lights at all back then)

However it sounds like I am not going to be able to look for these things myself.

Thanks for your post.

 

Like someone already said turn the car on but do not start and shift through the gears. It should shift smoothly between all gears. Of it does this then the transmission is probably ok. If yOu jack up the car you will see the actuator it sits just above the rear crossmember second from the back. Use two floor jacks and lift it up and make sure the actuator does not move up or down because it can hit this cross member. If that's seems ok then take for a short drive and ensure speedometer is working as others have said one way the tranny knows what gear is by the speedo. This is probably working because it shifted to fourth after neutral indicating it was sensing speed. It could also be the gearbox sensor is malfunctioning or the throttle position sensor. It seems that basically it has to be one of these. All these inputs go to the tcu and it analyzes them to select gears. You could check the gearbox sensor by slowing down to a stop in second it should automatically shift down to first if this does not happen I think the gearbox sensor or plug is bad. I'm not positive but that seems logical however I have not had this exact problem. I do believe mine shifts to first if I stop in second though. Maybe Dave can go for a drive and check.

 

With your mention of 40 in reverse sounds like that speed sensor mentioned earlier. It could be bad.

 

Wow, thanks - another great advisory post.

It does sound like it could be the speed sensor. If the computer doesn't think we're moving because the speedo says we're at 0, then it won't let me shift above 2nd. However when flying along in neutral and popping it back in gear, the computer is matching the REVs (which are working) and therefore choosing a higher gear.

My car still shifts down through the gears, which doesn't surprise me, I'm guessing its the computer matching the rev counter, ignoring the speedo. I can't shift UP because the speedo says I'm stationary. So as I slow down I shift down through all the gears and end up in 1st.

All beginning to make sense now.

Thanks so much! Now to try and get it up on ramps and see if there's a loose connection.

Cheers,
Richard

 

I'm tending to agree with you from the symptoms, and from the advice I've been given on here. A loose or faulty speed sensor might be sending faulty numbers to the dash.

Thanks!

 

Grant, yes, if you are in second and come to a stop, the trans will auto shift to first. It will do this if you are in 3rd too. Not something I do, but had it happen with an abrupt stop.

 

My 1999 had the identical problem it was a transmission sensor that they had to drop and drain the tranny to replace.

 

Just to confirm, I took a ride yesterday and came to a stop in 4th. The tranny autoshifted down to first.

 

The F1 transmission will auto down shift from any gear after the engine revs drop below 1300 or 1200(?) rpm whether you are in auto or not.

The speed sensor is an easy replacement, but yes, you will need to drain the tranny....or do the swap reallllly fast

 

If all else fails, this will fix it...

Drain the Trans and replace the Electro Mag F1 sensor (#168729) and the speed sensor (#149095)

 

That's what I though, from what I read in the WSM it would make sense that the gearbox sensor then is really only there to confirm you are stopped. This would ensure it auto shifts to first and also prevents reverse shift unless stopped as well. Not sure how the throttle position works in the tcu other than allowing 2 nod gear when speed sensor is faulty.

 

This is true for all gears except first, but I don't think it shifts to first unless you are stopped. Just what I noticed, I think.

 

The speedometer sensor I think can be replaced without dropping oil, but the gearbox sensor on bottom your right in that it's a good drain plug.

 

+ 1. Except I just bought the GB sensor and it's like 300 bucks. I would check the plug first mine got bent and was leaking so it works but leaks so I needed to change it.

 

Correct.

 

Oh dear. Thanks for the info, I hope its the speed sensor not the tranny sensor...

 

Cool, thanks for the part numbers too. Very helpful.

 

Interesting - because the F1 fluid looks low too, below MIN on the dipstick. So perhaps I have a leaking plug as well.

Now need to get it on a ramp somewhere.

Cheers

 

No prob, the same issue as mine, I had to drive over 200 miles like that.
Lucky it was all freeway on I-5, so I just stayed in 6th gear the whole way

 

Nice drive down I-5! Mine was in town traffic, through multiple roadworks! Not quite so smooth, but made it in one piece

Cheers,
Richard

 

The f1 fluid in the back up top with the screw on lid should be low. If you fill it tO max it will overflow.

I was referring to the gearbox oil in the gearbox/transmission.

 

Update, I finally took it to the dealer and they're investigating.

Of course on the way there, the speedo started to work again. The gears started to work again.

When I set off, I was still unable to change out of 2nd to 3rd without putting it in neutral first.

At the 3rd traffic light however, all seemed suddenly to start working again.

I very nearly didn't take it in - but I'd like to find out why its happening.

Now dealer says it might be the send unit, but they're also checking to see if its an electrical fault.

Thoughts anyone?

Thanks!
Richard

PS Forgot to mention - the red transmission warning light is still on