smg issue

[mat kelly]

Hi guys im looking for some help, Newbie here so please go easy.
i have a 2004 Z4 3L smg , the gearbox light came on the other day and it wont let me change gear manually, also it will not drive above 50mph, its like a limiter kicks in at 50. the car works ok in full auto, goes into gears and changes up and down as expected (up to 50mph) ive plugged it in and it comes up with.
229a dme can fault management EGS
5084 smg selectorlever hall sensors single fault
5080 smg selector lever analog line 2
can someone point me in the right direction where to look, im assuming its a broken wire somewhere but i have no idea where
i have had it plugged into INSTA and same faults, however when plugged in every command i put in either on gearstick or paddles showed on laptop screen, so in my head the ecu is getting the signals from my inputs but not getting to the gearbox,

[mat kelly]

PXL_20231214_130725372.MP (1).jpg (233.16 KiB) Viewed 366 times

[bigwinn]

patriot66

is your man for SMG issues hopefully he will be along in a min

[patriot66]

Hi Mat. You say the car works/drives partially in auto mode up to 50mph but not manual. Presume you've checked some basic things first. What condition is the battery in ? Have you checked the gearbox hydraulic fluid reservoir level ? Any leaks from gear selector whilst your in that area ? Check/replace the 'salmon' SMG relay in the engine bay box ? Can you hear the hydraulic pump pressurising when you unlock the car ?

[mat kelly]

hi yes it drives as normal in full auto (city) mode, up to 50 mph, battery is good , when parked with engine off i can hear the priming and it goes from P into N and then D no problems , sport button works as it should, everything else on the car is ok, i would have thought if it was fluid then it wouldnt work in auto mode ???
no leaks from anywhere
its frustrating as hell
like i said im new to the z4, i had a turbo mx5 before this
is there any way to find this line 2 fault or am i getting the multimeter out and doing a continuity test on the loom to the box,
thanks for the help

[mat kelly]

I will check all fluid levels tomorrow tho, one other thing i have to put it into D with ignition on / engine off when i first start, if i start engine first it will not go into D it flashes between R and N , once its gone into D with engine off if i put into N and start engine it then selects D , (yellow cog light permanently on)

[patriot66]

I would think it unlikely to be a straight break in a gearbox wire. Probably the shift or selector sensor located on top of the gearbox, or the ESG itself which I think is in the engine bay relay box...or a combination thereof !

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Screenshot_20240105_192525_eBay.jpg (129.28 KiB) Viewed 275 times

[mat kelly]

looks like its a box drop for this then , ill get hold of a relay first but may be a few days now before i get a chance to look at it, ill let you know

[patriot66]

Definitely worth eliminating the relay and ESG first. You may not need to drop the box to check a few things. There's a fair bit of access on the non-exhaust/left side. Fingers crossed

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[mat kelly]

Update, been having a look today and found evidence of rodents , so does anyone have the wiring diagram for the smg, i honestly thing something has been chewed, gunna get it up in the air tomorrow and try trace all the wires from the ecu down to the box, hopefully its an easy spot, got a loom they have taken the outer sheath off but no exposed wires inside

[patriot66]

The little buggers ! Hope you get it sorted.

[Zedebee]

Thought a pin out might be more helpful as the wiring diagram is tiny and doesn’t screen shot well:

A70010 Sequential manual transmission (SMG)

Plug connector overview

Number X-pin, colour Description
X70011 9-pin, blue Plug connector Sequential manual transmission (SMG) Module 1
X70013 52-pin, blue Plug connector Sequential manual transmission (SMG) Module 3
X70014 40-pin, blue Plug connector Sequential manual transmission (SMG) Module 4

Pin assignments at plug connector X70011

Pin Type Description /Signal type Connection /Measuring notes
1 E Terminal 15 Fuse F9
2 Not used
3 Not used
4 Not used
5 M Ground Ground connector
6 Not used
7 E Terminal 30 B+ potential distributor
8 Not used
9 Not used

Pin assignments at plug connector X70013

Pin Type Description /Signal type Connection /Measuring notes
1 Not used
2 Not used
3 E Signal, gearshift position L2 Electronic vehicle immobilizer (EWS)
4 Not used
5 E Signal, CAN bus low, DSC sensor Rocker switch, left
6 E Signal Selector lever position L0 Selector lever
7 E Signal Selector lever position L1 Selector lever
8 E Signal Selector lever position L2 Selector lever
9 A TD signal Connector TD signal
10 Not used
11 E Signal, load cutout Connector Load cut-out
12 E Signal, terminal 50 via vehicle immoblizer Fuse F32
13 E Signal Shift lock selector lever lock Shift lock selector lever lock
14 M Sensor ground Connector Sensor ground
15 E Activation, indicator lamp Brake light switch
16 Not used
17 Not used
18 Not used
19 Not used
20 Not used
21 Not used
22 Not used
23 E Signal Selector lever position L3 Selector lever
24 E Signal Selector lever position Sport Selector lever
25 Not used
26 Not used
27 Not used
28 Not used
29 Not used
30 Not used
31 Not used
32 Not used
33 Not used
34 Not used
35 Not used
36 Not used
37 Not used
38 Not used
39 Not used
40 Not used
41 Not used
42 Not used
43 Not used
44 Not used
45 Not used
46 Not used
47 Not used
48 Not used
49 Not used
50 Not used
51 Not used
52 Not used

Pin assignments at plug connector X70014

Pin Type Description /Signal type Connection /Measuring notes
1 A Negative activation Reversing light relay Reversing light relay
2 A Voltage supply Clutch position sensor Clutch position sensor
3 E Signal Selector angle sensor Selector angle sensor
4 E Signal Clutch position sensor Clutch position sensor
5 Not used
6 Not used
7 Not used
8 Not used
9 Not used
10 A Activation Solenoid valve, brakes Solenoid valve, brakes
11 A Voltage supply Gearshift sensor Selector angle sensor Hydraulic pressure sensor Gearshift sensor Selector angle sensor Hydraulic pressure sensor
12 E Signal Gearshift sensor Gearshift sensor
13 E Signal Hydraulic pressure sensor Hydraulic pressure sensor
14 Not used
15 M Sensor ground Clutch position sensor
16 M Sensor ground Gearshift sensor Selector angle sensor Hydraulic pressure sensor
17 M Ground Ground connector
18 Not used
19 Not used
20 A Activation Solenoid valve 2, gear Solenoid valve 2, gear
21 E Voltage supply, transmission electronics via main relay Fuse carrier, engine electronics
22 Not used
23 E Positive activation Rpm sensor, transmission main shaft Rpm sensor, transmission main shaft
24 M Negative activation Rpm sensor, transmission main shaft Rpm sensor, transmission main shaft
25 Not used
26 Not used
27 Not used
28 Not used
29 Not used
30 A Activation Hydraulic pump relay, SMG Hydraulic pump relay, SMG
31 Not used
32 A/E Signal Diagnostic link TXD DME control unit
33 Not used
34 Not used
35 Not used
36 E/A Signal CAN bus high DME control unit
37 E/A Signal CAN bus low DME control unit
38 Not used
39 A Activation Solenoid valve 1, gear Solenoid valve 1, gear
40 A Activation Solenoid valve, clutch Solenoid valve, clutch