TD5 D2 brake light permanently on

DrecklyD2 said:

About to un pin the wire as you suggest and apply 12v but as it already shows 12v I'm not holding up much hope.
I will try it though, thank you

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As long as you have 12V on that wire no need to unpin it, that 12V is sent by the SLABS ECU to extinguish the LED cos it has positive feed one side from the IP and once positive is applied to it's other side it should go out, that's how all the warning lamps are working... IMO the problem is in the IP... i presume that the 12V drops there if you apply the handbrake?

sierrafery said:

As long as you have 12V on that wire no need to unpin it, that 12V is sent by the SLABS ECU to extinguish the LED cos it has positive feed one side from the IP and once positive is applied to it's other side it should go out, that's how all the warning lamps are working... IMO the problem is in the IP... i presume that the 12V drops there if you apply the handbrake?

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I haven't tested for voltage drop but will do shortly however.
While the clocks were out I removed the circuit board to find that some dirty b*******d had stuffed tin foil in the recess to cover up the gearbox over heat warning lamp. This too is permanently on.
Do you think there is a link here?
Nanocom shows no gearbox faults and the vehicle drives as it should.
Your help is greatly appreciated, thank you
Tom

DrecklyD2 said:

While the clocks were out I removed the circuit board to find that some dirty b*******d had stuffed tin foil in the recess to cover up the gearbox over heat warning lamp. This too is permanently on.
Do you think there is a link here?

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Yes, it's quite possible cos as long as you have 12V on the wire to the brake warning it should deffinitely be off, it's supposed to come on when it gets earth from the handbrake or reservoir's switch or if the 12V is cut by the SLABS ECU... then the IP's internal logic circuit brings the light on like on the self test... the warning lights are made to work this way as to come on if a system remains without power due to a blown fuse or the power is cut on the warning lamp's wire by the diagnostic protocol due to a fault if you see what i mean

sierrafery said:

Yes, it's quite possible cos as long as you have 12V on the wire to the brake warning it should deffinitely be off, it's supposed to come on when it gets earth from the handbrake or reservoir's switch or if the 12V is cut by the SLABS ECU... then the IP's internal logic circuit brings the light on like on the self test... the warning lights are made to work this way as to come on if a system remains without power due to a blown fuse or the power is cut on the warning lamp's wire by the diagnostic protocol due to a fault if you see what i mean

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Have now cut the wires from the trans temp sensor and the overheat lamp has gone out but the handbrake light remains.
Will continue to see what I can find
Thanks again for your input, very valuable

The trans temp sensor warning works in a different way as it's triggered directly by the temp switch, it's not connected to any ECU, if it went out by cutting the wire the problem is with the transmission temp switch or it's circuit... what i explained with the positive feed on the earth path for warnings is valid only for those which are connected to one of the ECUs

DrecklyD2 said:

Have now cut the wires from the trans temp sensor and the overheat lamp has gone out but the handbrake light remains.
Will continue to see what I can find
Thanks again for your input, very valuable

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Voltage drops to 10v on handbrake wire and also on reservoir wire.
Voltage at instruments is 12.8

DrecklyD2 said:

Voltage drops to 10v on handbrake wire and also on reservoir wire.
Voltage at instruments is 12.8

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It's a drop along the wiring not a problem, it should drop completely when the handbrake is on.... here's about the brake warning

sierrafery said:

It's a drop along the wiring not a problem, it should drop completely when the handbrake is on.... here's about the brake warning

View attachment 291648

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Doesn't drop below 10v, it's always live handbrake on or off

DrecklyD2 said:

Doesn't drop below 10v, it's always live handbrake on or off

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Then there is another issue too there cos the handbrake switch should close to earth when it's applied

sierrafery said:

Then there is another issue too there cos the handbrake switch should close to earth when it's applied

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Will keep looking and testing.
Thanks again for all your time and input, very much appreciated

DrecklyD2 said:

Will keep looking and testing.
Thanks again for all your time and input, very much appreciated

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Both the handbrake and reservoir switches work as they should returning the values they should.
So handbrake off 12v
Handbrake on 0v
I am now investigating the SLABS ECU outputs on the pink and orange.
Shame it's not on the wiring diagram

DrecklyD2 said:

I am now investigating the SLABS ECU outputs on the pink and orange

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It's C0504 pin 9 , appears in the ABS system's diagram but as long as the warning stays on when it's +12V on that wire the problem is in the IP for sure

sierrafery said:

It's C0504 pin 9 , appears in the ABS system's diagram but as long as the warning stays on when it's +12V on that wire the problem is in the IP for sure
View attachment 291677


View attachment 291678

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Thank you

see

mystery said:

see

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Thank you, will study them later

sierrafery said:

It's C0504 pin 9 , appears in the ABS system's diagram but as long as the warning stays on when it's +12V on that wire the problem is in the IP for sure
View attachment 291677


View attachment 291678

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You Sir, are right on the money. Plugged in another IP and all is well, handbrake light goes off when released.
Thank you for your time and help
Tom

Welcome, i'm glad it's clear now... even though replaceing the IP is not a perfect happy ending, be aware that if it has higher mileage you'll be stuck with that and nothing can be done, if it's lower mileage you can synk it with the BCU to get the real one, just disable the odometer error warning in the BCU instrument pack settings

sierrafery said:

Welcome, i'm glad it's clear now... even though replaceing the IP is not a perfect happy ending, be aware that if it has higher mileage you'll be stuck with that and nothing can be done, if it's lower mileage you can synk it with the BCU to get the real one, just disable the odometer error warning in the BCU instrument pack settings

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Thanks for that.
Luckily the mileage was lower so have done a sync with BCU and all is normal again.
Until the next fault

DrecklyD2 said:

Thanks for that.
Luckily the mileage was lower so have done a sync with BCU and all is normal again.
Until the next fault

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And the next fault is now showing
The ACE warning light is permanently on in orange not red.
No ACE is fitted so is it just a case of cut the warning feed for that lamp.

You can't cut the warning feed for that lamp cos it has feed through the IP's internal circuit, it's turned off with positive feed from the ECU like the brake lamp... as you have nanocom disable it in the BCU instrument pack settings ...after you set up all the warning lamps according to the vehicle's equipment go to "write settings", quit the menus and power down nanocom from it's screen, turn ignition off then wait 60 seconds untill you unplug it otherwise it can alter settings without request or not save them.... check if all the warning lamps are working as they should after that anyway and if it's not OK go back in that menu and see what was disabled by nanocom.