Aston Martin DB7, DB9, DBS, Vantage V8, Vanquish, and Classic models

GEARBOX FAULT FUNCTION REDUCED message & gross gearbox sound

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Old Nov 24, 2023 | 01:10 PM
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GEARBOX FAULT FUNCTION REDUCED message & gross gearbox sound

Unsettling sound ostensibly from my gearbox! Has anyone had this issue? Or any theories?:

On a recent drive, I was coasting in Neutral then dropped it into 2nd gear which is what the car chose for my speed- I’ve done this many times and on this forum we’ve already established that this is totally OK method that ASM/Sportshifts are designed for, so I don’t *think* this is the issue but who knows. When changing N->2nd, I heard a loud noise. Quite oddly it sounded very much like when your front lip spoiler scrapes against a steep concrete driveway ramp (but it wasn’t this because I was on a very flat road). This exact thing happened later but at 50% of the loudness, then again at 25% loudness, then went away. Now I’m afraid to drive the car.

Some context:
Right before that drive, I received the “GEARBOX FAULT FUNCTION REDUCED” warning out of nowhere. I had simply turned on the car but hadn’t pulled away yet, in fact I’m pretty sure I was in Neutral the whole time. Eventually the warning message went away and I was able to drive normally. (I think this is coincidence but I should mention that I had just plugged in a new USB device that possibly messed with the Aston electronics causing it to lose its mind momentarily, this is hard to believe because it’s probably not coincidence that the display warning + noise happened together, but I know the Aston electronics are finicky!)

More context:
I recently had a Velocity AP clutch installed. In troubleshooting issues related to the clutch, we replaced the Brake Pedal Sensor, which apparently can cause clutch issues. That might explain the OBD code below.

OBD Scanner:
I ran some diagnostics and got the following codes, not sure if they’re related or just distractions:

• U1051 - Missed - Brake pedal switch (brake lamps) signal invalid

• P081C - Missed - Gear selector sensor 2 or 4 stuck closed (Reverse button switch contacts

• P0855 - Missed - Gear selector sensor 7 circuit high (Drive button) - open circuit/short circuit to power

• P081D - Missed - Gear selector sensor 5 or 6 stuck closed (Neutral button switch contacts

• P1601 - Active - ECU fault (internal faults including power latch relay)

*These codes were through my Foxwell OBD scanner, under the Marelli transmission control module section



 
Old Nov 25, 2023 | 01:58 PM
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Perhaps let us know the kind of car and year ?
 
Old Nov 26, 2023 | 10:54 AM
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Plugging in a USB device didn't have any impact on the powertrain. If clutch was just replaced a related fault would be most likely. Any fluid leaks under the car?
 
Old Nov 27, 2023 | 04:19 PM
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Originally Posted by MRCW
Perhaps let us know the kind of car and year ?
Ah my bad:
Aston Martin Vantage V8 4.3L (2008 Coupe)


 
Old Nov 27, 2023 | 04:27 PM
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Originally Posted by J doubleU
Plugging in a USB device didn't have any impact on the powertrain. If clutch was just replaced a related fault would be most likely. Any fluid leaks under the car?
Yes I agree re USB device, I didn't mean that the USB would actually affect the powertrain itself, I meant it could interfere with the car electronics which would lose its mind and display an error message. I've had weird behavior like that before, although admittedly the display really lost its mind as opposed to just one discrete message. Re fluid leaks- I don't think so, I'll check, but I'd think the under tray would catch at least the initial drips. Is there a sensor to monitor gearbox fluid?
 
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