2018 F30 320d M-Sport ZF8 Gearbox Issue After Engine Replacement

Killer-Velo Custom · 05-06-2020, 01:52 PM

Changed an engine in the above vehicle due to aqua locked engine. Used same spec engine from same MY vehicle. Bolted original zf8 gearbox to it & reinstalled to vehicle. Engine starts & runs fine, but gearbox will not shift out of park. Vehicle recognises gears are trying to be selected, as it asks for brake pedal or select button on shifter to be depressed, but it will not shift from park. The lever on the side of the gearbox is closed so transmission is live. There are no warning lights on & having had fault codes read, nothing shows up? Any thoughts or manual work rounds to be had?

Pobsey · 05-06-2020, 03:25 PM

Brake pedal switch connected?

Killer-Velo Custom · 05-06-2020, 03:28 PM

Yes, transmission picks up if brake pedal depressed or not. Did not raise as faulty when codes read....,,

Watsey · 05-06-2020, 04:23 PM

My understanding is that the TCU and the ECU (as well as various other control units in the car) have to all be coded into the car.

The ECU and the TCU operate in a continuous feedback loop. It may be that the new engine and the transmission don't recognise each other.

bishbosh · 05-06-2020, 04:50 PM

Agree, although if only replacing the engine you would leave the ecu as is. So it should still all work in harmony.

05-06-2020, 01:52 PM	#1
Killer-Velo Custom New Member 2 Rep 7 Posts Drives: BMW 320D M-Sport Join Date: May 2020 Location: UK iTrader: (0)	2018 F30 320d M-Sport ZF8 Gearbox Issue After Engine Replacement Changed an engine in the above vehicle due to aqua locked engine. Used same spec engine from same MY vehicle. Bolted original zf8 gearbox to it & reinstalled to vehicle. Engine starts & runs fine, but gearbox will not shift out of park. Vehicle recognises gears are trying to be selected, as it asks for brake pedal or select button on shifter to be depressed, but it will not shift from park. The lever on the side of the gearbox is closed so transmission is live. There are no warning lights on & having had fault codes read, nothing shows up? Any thoughts or manual work rounds to be had?
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05-06-2020, 03:25 PM	#2
Pobsey Lieutenant 185 Rep 475 Posts Drives: 2019 F31 330d / 2010 e87 118d Join Date: Mar 2011 Location: UK iTrader: (0)	Brake pedal switch connected?
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05-06-2020, 03:28 PM	#3
Killer-Velo Custom New Member 2 Rep 7 Posts Drives: BMW 320D M-Sport Join Date: May 2020 Location: UK iTrader: (0)	Yes, transmission picks up if brake pedal depressed or not. Did not raise as faulty when codes read....,,
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05-06-2020, 04:23 PM	#4
Watsey Major General 6399 Rep 8,489 Posts Drives: F31 330D sDrive M Sport Join Date: Jun 2015 Location: On sabbatical. iTrader: (1)	My understanding is that the TCU and the ECU (as well as various other control units in the car) have to all be coded into the car. The ECU and the TCU operate in a continuous feedback loop. It may be that the new engine and the transmission don't recognise each other. __________________ Current : F31 330sD, remapped, Ohlins Road & Track, Millway camber plates, Quaife LSD, Stoptech brakes + Pagid RSL1 pads all round, Weichers front strut brace, Eibach front & rear anti-roll bars, Michelin MP4S.
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05-06-2020, 04:50 PM	#5
bishbosh Lieutenant Colonel 838 Rep 1,991 Posts Drives: F30 335d Join Date: Oct 2013 Location: Sheffield iTrader: (1) Garage List 2014 BMW 335d [0.00]	Agree, although if only replacing the engine you would leave the ecu as is. So it should still all work in harmony.
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