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Twincam1986

E34 520i won't kick down

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I've tried searching but I can't quite find a similar problem to mine...

I've bought the above car today (M50 engine). I didn't realise when I bought it that the transmission programme error light is illuminated as the display is a little pixelated, but it is! Driving normally, the transmission seems to change up/down as normal but I've found that it will not kick down on the pedal and it changes up at around 3500rpm regardless of pedal position. It isn't stuck in one gear so doesn't appear (to me) to be in limp mode. It feels as though it is stuck in economy mode but the mode selector doesn't appear to be doing anything.

I have found in the service history a receipt for a replacement transmission in 2015 (part number 24001219955 from a 1994 520i). I was wondering if this gearbox would also have needed the ECU from the donor car and maybe it didn't get it, causing problems?

The battery and one of the battery leads was also replaced a couple of weeks ago, which I've read can also affect the transmission programme?

Does anyone have any suggestions on the best way to start diagnosing the problem? Is there a way to read the fault codes without a specialist scan tool as it's too old to be OBDII?

Any help welcome!

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Put your VIN in realoem.com and it will tell you which part number you should have. It will probably come up with 956 instead of 955 because they list the replacement part number. It looks right to me. There is a plate on the driver's side of the transmission just above the sump line. Use a mirror to view it from the passenger side (the exhaust is in the way on the driver's side). Make a note of the long ZF part number which should be 1056000081 and the BMW part number will be shortened to 1219955 (or 1219956). If that is the case, there was no need to do anything with the transmission control model - it would be plug and play.

 

Revving to 3500 rpm is way too high. I would have thought 2000 - 2500 rpm is more than enough. The kickdown is just a switch to ground and it is under the throttle pedal. You can test that it is working with a simple multimeter

 

If the gears are changing correctly 1 to 5 and reverse, the car is not actually in limp mode and the gear symbol/trans program message may well be just a fault in the cluster. Confirm that when you move the shift lever, the dash confirms the gear you have selected and that when you operate the mode switch it does the same. It should default to E (economy) mode every time you switch on and the display will read ED when you select D. Sounds a little like it is stuck (or wired) to stay in S (sport) mode

 

You need an ADS module not OBD to read these cars. Maybe if you post your location in your profile, somebody close may be will able to help 

Edited by whiskychaser

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Thanks for the reply.

 

I've just had a play with it after reading around on various forums. The display is pixellated but it's definitately displaying trans prog error once the car is started. With just the ignition on, you can make out the gear selector position and the mode selection. When it starts, this changes to a cog and is backlit orange.

 

Most posts I'm reading suggest it locks into 3rd or 4th when this error is displayed but I'm definitely getting 1-4. It feels normal under regular driving conditions, but it will change up at about 3200rpm in each gear when floored and won't kick down. It doesn't seem to go into 5th (or lockup, whichever it is) but revs beyond 3200rpm fine in 4th.

 

I've had the selector switch apart and cleaned the contacts but it made no difference. I also cleaned the mode selector switch. I did notice whilst doing that, that the selector itself doesn't lock into position, i.e you can select any gear position with the engine running or not, without pushing the button on the gear selector.

 

I checked the battery as I read that a voltage drop when starting can upset the system. The battery is 3 weeks old but is 56AH when the handbook recommends 65AH. I tried starting it with a jump pack attached in case it wasn't getting enough power with the 56AH but it made no difference and the car starts on the button with the smaller battery.

 

I need to read the codes really but trawling around to find somewhere with the kit to read a 1993 BMW gearbox ECU doesn't fill me with anticipation. I'm near Warrington if anyone knows of somewhere?

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As Whisky Chaser says, I wonder if it is stuck in Sports mode given the high rev point change.

 

Being able to select any gear without pressing the button is dangerous, that lock is, I assume, a safety feature to prevent accidental/incorrect gear selection. I would take the gear handle off, if the white rod is missing or broken, or is not attached to the handle, it needs sorting with either a replacement rod or handle. 

 

If you have the skills it is also worth replacing the capacitors in the cluster and separate auto cluster module so you can at least see what is going on. 

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Tim Pollock has a 520i auto in for breaking. Might be worth changing the box over for a known good one. 

 

Also worth testing the alternator output as a low voltage does throw the transmission error. It should be 14.0v to 14.3 volts with the engine running at 2k revs. 

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The high revs and the fact it will not go into 5th lead me to believe it may be in sport mode. Have to say I have come across cars with trans prog in the cluster and others with a gear symbol as they don't have check control. But not both together.

 

But hang on a moment.... are you sure that is a cog and not a '*' ? Is it showing *D? That means it is in winter mode. Maybe confirm what it actually shows with just ignition on and try it with the mode switch unplugged

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If I drive it gently it will change up lower than 3200rpm. However if i floor the throttle, that is the highest change point, so it won't hold on to each gear and it won't kickdown. It's odd, as I'd have thought if it were stuck in sport, it would be holding on to each ratio?

 

I'm not sure that there's anything wrong with the box, it seems more like an electrical issue of some kind or something with the peripherals. Again, I don't know but I would have imagined a problem with the box itself would have caused it to lock in 3rd as has been mentioned elsewhere?

 

Whiskeychaser - just typed out a reply on the other forum I'd posted this on, but it's awaiting confirmation from a mod, as there's a pic on it. :-D

When it's started, it just displays a cog with an exclamation mark. With only ignition on, it will display the gear selector postion and the mode and it always goes back to E each time. I can start the car in any of the 3 modes and it goes straight to the cog symbol once started. I've tried starting it with the mode selector switch unplugged and it;s the same result, cog symbol once started.

I don't mind a drive to Oldham if you're able to read the codes for some beer money

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All sport mode does is delay the upshift point. Depending on how much pressure you put on the loud pedal, that might only be as little as 500rpm higher than when in economy mode.

 

The kick-down switch has quite a strong spring. Not trying to insult you but it does take a bit of pressing. It can also be adjusted up by screwing it out of the floor. Just don't mangle the wires if you move it :) Maybe have a look at the switch and push the pedal down with your hand. You will soon see/hear if it is operating. Of course, you need a meter to ensure it is working.

 

When you get trans prog in check control, the gear and mode display (ED etc) is normally switched off so you don't see them any more. Cars like the 520i usually have a 'low' cluster without check control - they have a light with the gear symbol instead. But you seem to have a combination of both which is odd. All may be revealed  when the photo is available. Not sure of the restrictions here but it might be an idea to post it if you can

 

Keeping these things on the road is its own reward but it is very kind of you to offer. If we cant sort the issue here then you are more than welcome. And the tea is free too  :)

 

    

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14 minutes ago, whiskychaser said:

All sport mode does is delay the upshift point. Depending on how much pressure you put on the loud pedal, that might only be as little as 500rpm higher than when in economy mode.

 

The kick-down switch has quite a strong spring. Not trying to insult you but it does take a bit of pressing. It can also be adjusted up by screwing it out of the floor. Just don't mangle the wires if you move it :) Maybe have a look at the switch and push the pedal down with your hand. You will soon see/hear if it is operating. Of course, you need a meter to ensure it is working.

 

When you get trans prog in check control, the gear and mode display (ED etc) is normally switched off so you don't see them any more. Cars like the 520i usually have a 'low' cluster without check control - they have a light with the gear symbol instead. But you seem to have a combination of both which is odd. All may be revealed  when the photo is available. Not sure of the restrictions here but it might be an idea to post it if you can

 

Keeping these things on the road is its own reward but it is very kind of you to offer. If we cant sort the issue here then you are more than welcome. And the tea is free too  :)

 

    

Don't worry, I've stomped on the pedal :-D, you can feel when it clicks but there's no kickdown.

I'm probably just not describing the display very well. This is my cluster:

 

IMG%5D

 

 

This is the display with the ignition on. Photo is not clear but you can just make out that it says E on the left and P on the right as it looks a bit clearer in real life (both of these change ok when the mode is changed or selector moved when ignition is on but car not started). It does look like S on that photo, but it's E, you can tell the difference when you select S.

 

IMG%5D

 

This is the display once the car is started - just the cog, nothing else

 

IMG%5D

 

David Bailey I am not!

 

 

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OK. Confusion over. You don't have 'check control' where it gives you messages in plain English - like 'Fasten seat belts', 'Door open', 'Lights on' etc. You have the normal 520i cluster which just gives you the gear symbol if there is a problem :lol:

 

If you have a meter, just connect it between the kick-down switch and ground. When you press it, you should get continuity. If you don't, it isn't working. 

 

 If you don't find anyone closer, just drop me a PM and we can sort out a time/day to check it out.

 

 

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Thought I should update this in case anyone else has the same symptoms.

 

Whiskychaser very very kindly scanned the Transmission Control Module for me. It's showing Code 40 Engine Intervention. He was also able to inform me that code 40 equates to pin 40 of the transmission control module, which is in turn connected to pin 14 of the engine control module, which supplies throttle position. This pointed to either the throttle position sensor or a wiring fault between pin 40 and pin 14. With some instructions on how to test the TPS, it did appear to be slightly out of spec, so I ordered a new one.

 

Unfortunately, after fitting it today, that hasn't solved the problem. I'm awaiting a new multimeter to investigate things further. Massive thanks again to whiskychaser for all of his help so far!

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Just to update, this is finally fixed! After a lot of messing about, it transpired that the TCM was faulty. Swapping it for another with a matching part number has sorted it out.

 

I must say a massive thanks to whiskychaser who has been more than helpful and tolerant of my mithering, there's no way I would have gotten it sorted without his knowledge!

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