Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
Gear shift module not rising. No led indicator. PLEASE HELP!
My gear shift is not rising nor is the red LED indicator which tells you what gear your in lighting up.
I've scanned it using an AUTEL see images below for codes. How do I fix it!? Thank you so much you kind people!
P0850-64 P/N switch input circuit
U0402-00 Invalid data sent from Transmission Control Module (TCM)
U0404-68 Invalid data sent from Transmission Control Module
U0103-00 Lost communication with gear shift module (GSM)
U101B-87 Lost communication with gear shift module (GSM) - multiple bus
b1087-88 LIN bus A
U0103-63 Lost communication with gear shift module (GSM)
U0103-00 Lost communication with gear shift module
Click image to enlarge
Click image to enlarge
Click image to enlarge
27th Mar 2025 8:18 pm
jackvoyager
Member Since: 02 Oct 2020
Location: UK
Posts: 63
Off topic but I have a question:
What Autel model is this?
What can it do in Discovery?
I'm thinking about buying it.
I did note this handy override whereby you can pull the lever into changing gears.
Prior to this point where the selector does not rise and LEDs no longer lighting up.
I noted the selector started to rise slowly and jolty and it got stuck in selector positions a couple of times.
But now it won't rise at all. Nor light up. The Autel says there's no connection?
I managed to start it 2 days ago and the selector rose, light up and worked as it should. But now it's back not working... I've tried several times turning the ignition on and off. But nothing again.
How can I fix this?
28th Mar 2025 9:19 pm
discofever16
Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
Can some kind soul please point me in the right direction?
Thank you so much
30th Mar 2025 5:21 pm
jackvoyager
Member Since: 02 Oct 2020
Location: UK
Posts: 63
You have to remove the entire selector and look inside it. The knob is driven by an electric motor via a small toothed belt....maybe the belt is worn out or the motor, but you still have to remove the selector and look inside it...
31st Mar 2025 12:51 am
Moo D3 Decade
Member Since: 13 Aug 2010
Location: UK
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31st Mar 2025 7:00 am
discofever16
Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
Ok so the solenoid controls the selector gear position and the motor controls the rising of the selector.
What controls the LED? My LED indicator has vanished.
I'll test it with a 9v battery and see what happens.
Note: I unplugged all the harness around the module inspected it. Reseated it all and plugged it back in and bizarrely it worked perfectly including the LED indicator with no errors! The following day it reverted back to not working.
31st Mar 2025 7:35 am
Gary_P
Member Since: 03 May 2016
Location: Kent
Posts: 1796
The indicator light fault is quite common. Normally you need a new unit , but one or two on here have delved into the circuit board. Try searching on the forum. I believe it is normally a resistor that is at fault.Gary
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Discovery 4 HSE 2016MY
31st Mar 2025 8:57 am
jackvoyager
Member Since: 02 Oct 2020
Location: UK
Posts: 63
discofever16 wrote:
The following day it reverted back to not working.
I guess you'll just have to replace the resistors
I also had it working after reinstalling it and then the same "blockage" I replaced the resistors and it works to this day
31st Mar 2025 5:45 pm
discofever16
Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
So the resistors are to blame for NO LEDs? and No rising of the selector?
Do they need new resistors or just re-soldering / reseating?
Thank you guys
31st Mar 2025 6:00 pm
jackvoyager
Member Since: 02 Oct 2020
Location: UK
Posts: 63
The resistors certainly affect the correct operation of the knob...
You can drive without the backlight, but not without the knob, so I would fix the knob.
31st Mar 2025 6:39 pm
discofever16
Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
Does anyone know what is required to fix the LED indicator?
31st Mar 2025 10:00 pm
discofever16
Member Since: 14 Feb 2024
Location: yorkshire
Posts: 36
So I tested both the motor connector and the solenoid connector with a 9v battery.
The gear selector rose and also selected through the gears.
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