Gearbox Fault Light..

Hi All,

Have searched around for this but only found solutions to it, that suggest the battery is the issue, But I know it is not so wondering if anyone has any other ideas...

Long story short the BCEM got wet on Tuesday night, and caused everything to have a melt down, Once I got it home I stripped it out completely & de-watered it as-well as using the dehumidifier.

Cleaned everything up under the seat, cleaned off old corrosion that was on the board within the BCEM, and put it back together.

Slowly went through every check I could think of whilst testing each fuse. Everything works fine.

Everything was fine so I went ahead to start it, To find out the battery was only 10v. Which can be explained from Tuesday night when I was trying to turn it over (plus every light and windscreen washer was pumping away due to the BCEM being wet)

So Jump started it, perfect first time, took it for a drive to find out Gearbox Fault light was on.

- One thing I will say is when test driving it, The "Sport / Manual" button and lights did flicker on and off a couple of times.

Tried it again this morning turn't over and started straight away but still have gearbox fault.

Does anyone have any suggestions on anything else to try? Or have access to a Diagnostic machine in the Surrey area?


p38
1997
2.5 | Auto

It's will be wet/corroded connections somewhere or low battery volts. If the voltage drops too far when cranking it wil log that fault.

Datatek said:

It's will be wet/corroded connections somewhere or low battery volts. If the voltage drops too far when cranking it wil log that fault.

Click to expand...

I am guessing it's logged the fault as the battery was pretty low.. Anyway to clear this without plugging into a computer? Or should it clear its self?

You state confidently it's not the battery and then go on to explain you only had 10 volts and had to jump start the car - if your battery was in that state it would take a series of lengthy drives to charge the battery fully. Your battery requires charging.

StuckAgainSteve said:

You state confidently it's not the battery and then go on to explain you only had 10 volts and had to jump start the car - if your battery was in that state it would take a series of lengthy drives to charge the battery fully. Your battery requires charging.

Click to expand...

As stated the battery was only on 10Volts due to the issues or everything running on it none stop and trying to turn it over.

The Battery has been on a trickle charge & is holding charge perfectly fine.

Drove for about 40 miles with it yesterday to run the battery up then everything was perfectly fine with starting it this morning and last night.

I shall though try a second battery and see if that makes a difference.

stewd said:

As stated the battery was only on 10Volts due to the issues or everything running on it none stop and trying to turn it over.

The Battery has been on a trickle charge & is holding charge perfectly fine.

Drove for about 40 miles with it yesterday to run the battery up then everything was perfectly fine with starting it this morning and last night.

I shall though try a second battery and see if that makes a difference.

Click to expand...

I would have helped if you had stated you recharged the battery after the 10 volt issue, unfortunately I've got a Microsoft crystal ball and it won't boot!

stewd said:

As stated the battery was only on 10Volts due to the issues or everything running on it none stop and trying to turn it over.

The Battery has been on a trickle charge & is holding charge perfectly fine.

Drove for about 40 miles with it yesterday to run the battery up then everything was perfectly fine with starting it this morning and last night.

I shall though try a second battery and see if that makes a difference.

Click to expand...

Neither a trickle charger or a 40 mile drive are going to fully charge a flat battery. The trickle charger could take days.

StuckAgainSteve said:

I would have helped if you had stated you recharged the battery after the 10 volt issue, unfortunately I've got a Microsoft crystal ball and it won't boot!

Click to expand...

... I hear there is a service pack that will fix that problem.

How did the becm get wet? did you also have water in the other footwell where the gear box ecu is and can produce said fault?

Datatek said:

Neither a trickle charger or a 40 mile drive are going to fully charge a flat battery. The trickle charger could take days.

Click to expand...

it took my battery 3 days to fully charge using a trickle charger so perhaps take the battery off and recharge it fully and get it tested then you will know for certain if its the battery that it causing the problem

I would have thought a 40mile drive would charge enough to not throw up faults
Mine can recharge enough to not throw up faults in 2 or 3 miles.
Id be more interested in if the gearbox ecu got wet or if a short in the becm when it was wet could have damaged it

gfromleeds said:

I would have thought a 40mile drive would charge enough to not throw up faults
Mine can recharge enough to not throw up faults in 2 or 3 miles.
Id be more interested in if the gearbox ecu got wet or if a short in the becm when it was wet could have damaged it

Click to expand...

If the battery is very low, 100 miles will not recharge it, especially if the alternator is not putting out the correct voltage.

Datatek said:

If the battery is very low, 100 miles will not recharge it, especially if the alternator is not putting out the correct voltage.

Click to expand...

Thanks for the info everyone.

Have tested battery and alternator all good, put a brand spanking new battery in as-well, no joy..

But now.. I have the following (still in 3rd only)

Sport / manual light next to gear knob, flickering on and off every now and then (only sport light).

No longer gearbox warning light on. Just the message each time the sport / manual light flashes..

Thanks for info about passenger side footwell, just taken seat and seen water has been in there as-well, currently drying it out.

Also to note. Have tested X, Y & Z sensors via autologic and everything is reading fine on them.

Druim said:

How did the becm get wet? did you also have water in the other footwell where the gear box ecu is and can produce said fault?

Click to expand...

I will upload the picture later of how it got wet.. Being helpful and helping the Local Residence moving Sandbags and evacuating people.

Thanks for suggestion on under passenger seat,

Taken both ECU's out, and stripped down, all cleaned out & dried. Put back in.

No gearbox fault ... But sport light on when first start car. Press button.. Gearbox Fault..

Can now change to Low Range though, Still no P/R/N/D on dash...

So.. Leaving overnight to fully dry / any moisture, Will try in morning. Otherwise have sourced both ECU's for collection tomorrow if problem is still there.

stewd said:

I will upload the picture later of how it got wet.. Being helpful and helping the Local Residence moving Sandbags and evacuating people.

Click to expand...

Watching the Sky rolling coverage of the floods the other day = I spotted a couple of P38s helping out (presumably the local 4x4 response club) - "Are they insane or very brave?" I thought to myself as P38s and water are not a good mix!

StuckAgainSteve said:

Watching the Sky rolling coverage of the floods the other day = I spotted a couple of P38s helping out (presumably the local 4x4 response club) - "Are they insane or very brave?" I thought to myself as P38s and water are not a good mix!

Click to expand...

I must have missed that
My p38 regularly gets a dunk in about a foot but even then its only for 2 or 3 seconds
Id never dream of keeping it submerged for any length of time

stewd said:

I will upload the picture later of how it got wet.. Being helpful and helping the Local Residence moving Sandbags and evacuating people.

.

Click to expand...

I wonder if you could get any of that unlimited funds the numptys at no10 have promised
after all it is flood damage

You can ford quite a remarkable depth of water in a P38 so long as the suspension is set high and you keep moving so the rest of the car (and the critical ECUs) is sat in the trough of the bow wave you create, stopping in deep water and loosing that vital trough is when water could get in and start a raft of electrical problems....

BOOMER said:

You can ford quite a remarkable depth of water in a P38 so long as the suspension is set high and you keep moving so the rest of the car (and the critical ECUs) is sat in the trough of the bow wave you create, stopping in deep water and loosing that vital trough is when water could get in and start a raft of electrical problems....

Click to expand...

Was a good 3foot deep for 1.5 / 2 miles, It wasn't the Depth I don't think that killed it,

door seals Arn't as good as I thought they were..!

--

Tried both ECU's again this morning, No Joy, So have the two on order and arriving tomorrow by 9am.