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2004 BMW E46 320i Touring
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Discussion Starter · #1 · (Edited)
I'm having an EGS error reported by INPA.

49 Gear check.
Shifting up from 4>5

This started showing up about 800km ago. No rough shifting but bouncing revs on deceleration. To me it feels like the lock up clutch is engaging and disengaging during deceleration. The reported slipping in INPA, I can't notice.

I have had my auto box serviced by ZF here in the Netherlands. Before that service there was some bouncing of revs during deceleration from 60 kph
After the service and driving for a bit the auto box shifted as new and was very solid. Now about 9000 km later it developed the bouncing revs decelerating from 90 kph. It's also a bit more pronounced.

Since my 2004 320i touring has 270000 Km or 170000 Miles on the clock I'm going for the cheapest option first and check the oil level, but assuming this is good is there anything else I can look at?

Could this bouncing of revs be due to pressure issues in the trans caused by the pressure regulator or one of the solenoids?
 

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When you say bouncing revs, do you mean multiple times, or just as you start the deceleration. It is normal for the revs to jump up when you take your foot off the gas as the TC clutch is immediately disengaged to make the deceleration smoother.

If it doesn't seem to be just as you decel, is it doing this in all gears (when driving in manual mode) or just one?
 

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Discussion Starter · #3 ·
It is definitely bouncing revs. And at a very specific speed window.
Driving a steady 90 kph (55 mph) the trans is in 5th and lock up engaged. I take my foot off the throttle and revs will decrease a bit and after a second drop a further 500 rpm.
When it drops down to about 1200 rpm it seems to me the lock up clutch engages again and brings the rpm up by 500.
The trans will bounce the 500 rpm up and down until the car has decelerated to about 70 kph (40 mph). There the trans will settle on about 1000 rpm till you come to a stop.

Before the service at ZF the trans had this behaviour when decelerating from 60 kph. After the service where a flush and a deep clean of the valve body took place there were no issues for about 9000 km.

As far as I can tell there's no leaks on the trans and I'm assuming oil level is correct.
Hopefully I'll have some time this weekend to double check the oil level, but I have a suspicion the issue is related to pressure issues or a TC that's on it'a way out.

Any insight is very much appreciated!

I did check your DIY's but I do believe the issue above isn't covered.
 

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E30M3 Race F10 535 R1150Rt M Coupe
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I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
 

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2004 330Ci 115k miles
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I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
All the USA E46s with AT have a PWM-controlled variable TC lockup clutch, regardless of engine displacement.
 

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E46 F10 W204 W212
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And I think the difference was the amount of friction surfaces for the lockup clutch. It’s in the training manual somewhere.
 

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2004 BMW E46 320i Touring
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Discussion Starter · #7 ·
I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
My 320i definitely has a locking torque converter. The ZF 5HP19 transmission and torque converter for the M54B22 do have different part numbers compared to the 325 and 330. No clue what the difference is exactly but the transmissions for the 325 / 330 and 320, as far as I can gather, behave and operate the same. So I'm hoping someone here can guide me in the right direction to diagnose the issue.
Not looking forward to walk into a transmission shop and all they give me is the "need to rebuild/replace the tranny" line. I also would like to DIY and actually learn something along the way.
 

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What about live data from INPA?
Can you see pressures and valve positions?

I've never had an autobox, but other systems let you look at
useful diagnostics data like brake pressures, wheels speeds, etc.

all I got
t
no lockup mode.
 
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There isn't any way of working out the pressure, but if you have ISTA, it shows the voltage being applied to each solenoid. This can sometimes be helpful when diagnosing an issue.

Tim, is it only occurring in 5th? If you are at the same speed in 4th does it exhibit the same behaviour. I'm trying to work out if the problem might be with an individual clutch in the transmission itself or it might be with the TC clutch.

Of interest, the TC clutch is a single plate type, albeit the TC is a different spec for each transmission. The variation in transmission number is for differences in the number of friction/steel disks in some of the transmission clutch packs.
 

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Discussion Starter · #11 · (Edited)
Gentlemen.
Let me first say thank you so much for the extra info and suggestions!
I'm hoping this will lead me and hopefully others to a resolution.

What about live data from INPA?
Yes on that. Info as @BaliDawg states is there but at the moment only have INPA running on a laptop that doesn't hold a charge. So I can check the info only while stationary. There is an option to check the function of the solenoids. They all work according to INPA. I'm thinking it's only a check if they go on / off?

There isn't any way of working out the pressure, but if you have ISTA, it shows the voltage being applied to each solenoid.
Wish I had ISTA-D in this case. I gather it's a pain to get your hand on and working?

is it only occurring in 5th? If you are at the same speed in 4th does it exhibit the same behaviour.
In 5th it's way more pronounced, but it does happen in 4th while in manual mode. When I have time I'll make a video to clarify better.

My trans runs fine when in Manual mode btw. Are your problems present at all settings?
Issues seem the same in manual and sport mode. I do need to take a more systematic approach at checking this though. I've been busy and the moments I have been able to check, it's been busy on the roads.

In the meantime bit more info about the car before I'm able to get it on a lift and after that take it for a methodical test drive.

- Transmission has been flushed and valve body has been cleaned by ZF service center about 9000 Km ago. Filter was original to the car and I assume oil had never been changed before 🤦‍♂️. The service did resolve previous bouncing revs issue.
Bouncing of revs previous to the flush did not produce an error in INPA.

  • EGS was already on the latest software (7546092) I have a feeling this had been done by a previous owner.
  • Resetting adaptations for EGS does nothing to the rev bouncing.
  • DME has been updated by me resulting in a waaaayyy smoother engine. No difference to behaviour of the trans.
  • Been on a hunt to get fuel trims to a minimum (spark plugs, pre cat O2 sensors, VCG, fuel filter, fuel pump and DISA replaced. A vacuum leak here and there has been plugged). LTF's are around 3% to 4% at the moment. CCV and a shitty thermostat (car is running a bit cool) are likely culprits to the remaining percentage points.

My theory is that engine health does not really relate to the bouncing revs in this case, but I might be very wrong.
 

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Another way of determining if it's the TC clutch is to compare transmission analog outputs as the bouncing is happening. You will need INPA working as you drive and the problem is occurring.

Open the TCM then go to 'status', then 'analog values'. Observe the engine RPM, Turbine speed (transmission input), and output speed.

When there is slip in the TC (normal ops), the engine RPM should be slightly higher than the turbine speed. The more slip, the greater the difference between the two. The more locking of the TC clutch, the closer the two. The clutch never completely locks, so you should always see the engine RPM slightly higher than the turbine speed. You will see the greatest difference between the two when the TC clutch is completely unlocked.

At a constant car speed, the output speed should be constant, as this is the direct drive to the wheels.

So when the problem is happening at a constant car speed, what is happening with the turbine speed as the engine RPM bounces. Does the turbine speed bounce with it, or does it stay constant.

If the turbine speed is staying constant, then the TC clutch is engaging and disengaging, meaning the remainder of the transmission clutches are remaining clamped correctly. I suspect this is most likely the case, and is then a matter of determining why.

If the turbine speed is bouncing, then there is slippage downstream somewhere in the transmission.
 

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Discussion Starter · #13 · (Edited)
@jjrichar This is good stuff.
I’ll get on this as soon as I have a way to get a working laptop in the car.

Today didn’t go quite as planned as far as methodical test drives. After replacing the CCV, a job devised in the depths of hell, a simple thermostat change turned into a shit show because of an aftermarket radiator hose. People might be onto something advising to only use OEM... 🤦‍♂️
I did check the trans oil level. Was good.
 

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Discussion Starter · #14 ·
So I have been able to get INPA going on a laptop that actually works :)
Seeing the actual behaviour in INPA is pretty confusing and absolutely not what I expected.
Or I'm just horribly out of my depth. Which is actually very possible... Here to learn from people that actually know, so please bear with me.

It seems the transmission is working as it should and the engine is causing the actual bouncing of the RPM.

The video below shows the RPM bouncing twice shortly after releasing the throttle by about 300 RPM. The output and turbine speed both decrease as you would expect in a properly functioning transmission.


It all raises some questions for me.
These readings would lead me to conclude the transmission is fine and I should be looking elsewhere?
What is the 'Load signal' exactly and why is it able to read 192%?
What could possibly cause this behaviour? MAF? Fuel pressure? Some other sensors*?

A bit more info about the issue:

The rev bouncing started out of nowhere. The issue did not get worse during a period of time.
No noteworthy work had been done to the car right before the issue started.
I can replicate the rev bouncing at any time. Cold/warm/hot engine or transmission.
Resetting transmission adaptations will give no change.

Some other noteworthy stuff.

The Gear check 49 error in INPA has not returned since clearing it about 12 days ago.
Quite a few new errors in INPA (DME) have popped their head up with no ill effect to the drivability or errors in OBD Fusion:
217 Timeout CAN-Botschaft EGS1
8 Luftmassenmesser (this is the MAF)
91 TEG_UP_2
92 TEG_DOWN_2
The short story about the errors is that it could be me screwing around with updating the DME.

* The next one might be pure blasphemy. I installed a Febi exhaust cam shaft sensor. The idea was that a reasonably simple sensor should not cost €100 and what could go wrong? Right?
It is not giving any errors,but I have this little voice in my head that just goes "You're cheap and it all has to do with this crap sensor"

By now I'm in deep into the car in time and money. All of the issues, self inflicted or not, are motivating me to get to the bottom of it all. It's fun and at this point I just see it as acquiring skills and knowledge while driving a great car.

Any input is greatly appreciated!
 

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My opinion is that's the TC lockup clutch. Everything downstream of this seems to be working fine.

If the TC clutch seems to be working fine otherwise, it may not be the TC, and this is also the hardest to replace, as the transmission needs to come out.

I would be firstly replacing the valve body that contains the main pressure valve (the lower front valve body). If this doesn't work, I'd be replacing the small valve body that controls the TC clutch, the upper front valve body.

Link here to show you what I'm talking about.
 

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Discussion Starter · #16 ·
So it's been a while...
Since the issue of the bouncing revs on deceleration or coasting have not gotten worse and the transmission is doing just fine otherwise, other things have moved up in the priority list.
But I still want to get to the bottom of this. Ideally by DIY and at a reasonable cost. Preferably also before the trans decides to crap out on me :)

The TCC seems to be working as it should. For instance at higher speeds (115 km/h +) it seems to engage fully and does not seem to slip under load. Also at lower speeds it (partially) engages as it should.
@jjrichar I'm inclined to think it's a pressure issue in the valve body. If my reasoning is off please let me know! :)

My idea right now is to find a parted out transmission, taking out the valve body and replace / renew the parts where needed. This way I can work on the valve body while I can still drive the car. When complete I'll swap over the valve body and hopefully it resolves the issue. If not I have an extra transmission to rebuild.

Only problem is finding a 5HP19 for a 320i right now...
 

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Personally I wouldn't be replacing with parts from an old transmission. The parts you want to replace will most likely be worn in the replacement transmission. I'd be buying new valve body components. You only need the individual valve body housing, as all the other components will transfer across as shown in the link above. The replacement housing isn't expensive and is easily purchased from a ZF supplier. The changeover of the housing and individual parts is easily done in a few hours. Even if you have to pull out the entire valve body to replace the small housing that controls the TC clutch, it's done in an easy day.
 

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Discussion Starter · #18 ·
So a little update on this issue.
I have replaced the lower front valve body and filled the trans with fresh ZF Lifeguard fluid.
Short story is the shifts from 1st to 2nd are smoother and a an occasional thump on downshift are gone. The original issue does persists to some degree.

Strange thing is that the issue of the bouncing RPM on deceleration started to get less before I did the valve body replacement... The AC needed a bit of a refresh and I had it filled. This resulted in the bouncing RPM to almost disappear. AC on or off. WTF?

New lower front valve body and fresh fluid made the issue even less. It is still there but not nearly as annoying as it was. During all the research I also bumped into this by Sonnax. Seems like my problem is common enough to make replacement parts for. The description they use is also a bit more eloquent then I was using. "RPM surge on coast".

When dropping the oil pan it's clear my transmission is getting a bit tired. There was a grey dusting all over the valve body and filter and the magnets were, let's say, not clean. The fluid I thought was still pretty good was way darker then I expected after about 15.000 km of driving.
Also during the service at ZF (15.000 km ago) they apparently forgot to put one of the bolts back in the valve body. This is something I wasn't prepared for so had to put everything back with a missing T40 bolt at the front of the valve body.
Putting that bolt in as soon as I have time and motivation to deal with dropping the oil pan again.

Anyways. I'm a bit wiser DIY wise, but even more clueless on where the issue really came/comes from.
 
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