My '05 R53 6-speed auto transmission MINI has been running OK.

But, today, major clunk going from reverse to drive. EP is displayed on center console.

Transmission seems to be stuck in one gear, doesn't shift up or down (in either auto or manual modes), but I only got it up to around 40mph.

Tachometer is not working.

Lots of error codes that will not let me clear them with my code reader. Pics of them attached to this post.

I tried disconnecting the tach, but didn't really help.

The battery is pretty new and measuring 12.5V while off. Ground connection to it wasn't super tight, but tightening it didn't help anything listed above.

Any ideas??

Thx!

 

Do you have a sunroof? Is so, I would start by checking the BCM in the passenger side kick panel to see if it got wet from a loose drain tube. Also, the drivers side would drip on the fuse box and connectors which can cause some electrical issues.

You should be able able to check the drain tube connection by pulling down the headliner a few inches without removing too much stuff. I think you might be able to get away with just the sun visors and grab handle. Whether or not the tubes are loose, secure them with some small hose clamps. Some use zip ties, but I’ve read the hoses can still fall off if the roof/interior gets hot enough.

 

We took the headliner out once to do some glue repair to it and we added the zip ties to the tubes at that time.

We did get some rain here so I can check the BC1. Is it easy to tell if there’s any water damage present?

Some of the EP transmission threads I’ve found here on NAM talk about shorted wires but I don’t know where to be looking for those.

 

If the water damage is older, the wiring and connectors will usually have green corrosion and possibly falling apart. If it’s really recent you might see some water if it hasn’t already dried. I can’t remember if it was a MINI or another car but there might be a connector down on the side of the transmission that causes issues when oil, or some other kind of fluid leaks on it and the fluid wicks up into the connector and harness.

How many miles and has the trans fluid ever been changed?

 

80K miles on the car.

Trans fluid has never been changed. Is it lifetime fluid or should I change it?

 

Trans fluid is "lifetime" according to Mini service manual.
In reality, it's oil that collects debris and age. Never changing the trans oil is a surefire way to damage it.

If you heard a major clunk and then it's not shifting, it might be too late. At that point I'd advise a trip to your mechanic, because while it's too little information to really diagnose over the internet, that sounds like you need a new gearbox.

 

I accessed the BC1 and examined all the connectors that plug into it and that are on the BC1. Everything appears to be very nice physically without any sign of moisture past or present.

Photos attached.

 

Good to see no water damage. The fluid definitely isn’t lifetime, and I don’t remember if MINI revised their service recommendations, but VW uses essentially the same transmission and they issued a bulletin going from lifetime fluid to around 40k mile changes. Also, as posted above, the issue with the trans might be beyond fluid changes now.

A huge thread with trans and fluid change info is here: https://www.northamericanmotoring.co...ight=Aisin+80k

Some things to note if you want to try a fkuid change are:

• The car should be level
• Only about 2-2.5 quarts drains out at a time so it takes at least three changes to get over 75% of the fluid changed
• The car should be driven a short distance between changes
• You can get more fluid out if you drop the pan, but a large amount still remains in the torque converter.
• You can also change the strainer “filter” when dropping the pan
• The fluid temp must be in a specific range when setting the level. This is critical to getting the correct amount of fluid in the trans. Matching what came out might work, assuming the lever was correct before and you don’t spill anything during the process

Not sure if this will help, but unless you find an obvious cause for the issue, I think a fluid change is a cheap place to start before pulling the trans. If your first fluid change includes dropping the pan, you can inspect the valve body and solenoids.

 

To me those codes look an awful lot like either a wiring issue or a module failure on the other side of the KOMBI - or an issue with the KOMBI itself. I'm seeing both Can-bus and diag bus issues, right?

 

Yes. I think I might have a wire that’s shorted somewhere causing communication haywire but I don’t know where I should look?

Mechanic I usually use for a different car recently did a power steering system refresh of all hoses and pump. I saw a video online where a purple communication wire melted/shorted near power steering system. Not great photos but I do see something down there that looks a bit melted. Maybe it’s unrelated?

 

Read some other threads. I unplugged the tach, but that didn't seem to help anything. Does that mean I shouldn't try buying a used tach on eBay to see if that fixes any of the canbus issues?

 

My understanding is that the tach is just a display driven by the kombi. If unplugging it doesn't change anything, I doubt replacing it will either, but I haven't really messed with mine before.

 

I expect the tach isn't working because it looks like the kombi isn't getting engine speed info from the DME for some reason based on those codes.

The DME and ABS/DSC/ASC module are both on the can bus. I assume the gearbox controller or whatever it's called is on that same bus as well. I would certainly investigate any dodgy wiring you see in the engine bay.

 

I checked the battery today. 12.3V with engine off and 14.2V with engine running. Tightened up the ground side a little.

Disconnected the ABS module connector in engine bay and inspected. Looked OK.

Where’s the common rub areas I should be checking for a shorted/broken wire?

Or, is there any more scientific way to narrow down the portion of wiring that may be affected?

 

Fluid can drip on the transmission harness plugs and short them out causing CAN issues. I think there are two connectors and if contaminated, cleaning them with electrical cleaner is supposed to be a temp fix but replacing the harnesses is recommended for the long term.

Also check the TCU up on the firewall behind the pedals and the shifter assembly. Not sure how to diagnose the actual modules themselves, but maybe unplugging them might get the other CAN signals working. If so, that’s probably the issue and you can order a used replacement from Allmag or eBay or new from ECS. From what I’ve read, the TCU is supposed to be plug n play with no coding necessary.

 

OK. Those are great places to start.

First pic is from a week ago, second pic is from today.

My daughter had actually taken the attached photo just last Thursday of the speedo with only the traction warning light illuminated. So, I’m wondering if all these other issues stemmed from that?

Now, on speedo, the temp gauge is maxed (even when cold), tire pressure light is on, EP is shown where gear number usually shows, and traction light is still on.

 

On this image, is it possible to narrow down where my communication problem lies?

I ordered an OBD2 breakout box to do some simple testing I saw in some videos.

 

I’m digging around looking for dodgy wiring.

I disconnected this connector up by the front left of the engine bay. It appears like it was filled with motor oil??? Is that normal? I don’t think it’s dielectric grease. It seems like the color and consistency of oil. The plug and external wires were dry. Not sure how that could have gotten in there??

Is this bad or should I not worry about it causing my error codes?

 

That does look like motor oil, but I’m surprised there isn’t a trace of how it got in there.

If it was my car I would try cleaning the connector with something like CRC electrical cleaner and see if it fixes the issue. Then I would lightly pack the back/wire sides and the seam of the connector with dielectric grease after it’s been reconnected.

 

I found some other NAM threads of this exact problem, oil in this connector. Apparently, a failed oil sender sensor leaks only into the insulation of the wire(s) exiting the sensor and the pressure pushes it all the way over to this connector!! I replaced a failed oil sensor back in December.

I plan on cleaning connector with brake cleaner to see if it helps. I also have a used tach on the way.

Still would like to narrow down the system or possible wires that could be causing this craziness. I’m still looking for the culprits.

 

That's wild. I've also seen a similar issue with old speedometer cables.

 

I disconnected the main battery this morning and will let it sit all day to de-energize the computer system.

I plan on cleaning that oiled up connector with carb cleaner tonight and then reconnecting battery. Fingers crossed that makes some sort of improvement in the current error code status of the MINI.

 

Thinking back to the photo above from last week when only the traction control light was on...

Back in December is when my oil pressure sender failed and presumably was sending oil thru one or more wires over to that large cylindrical connector. Maybe THAT was what initiated the traction control light and the ensuing Christmas tree dash lights and error codes?

 

I'm really curious about what all the wires that go into this connector (located near front left of engine bay) are for. Does anyone have it shown on a schematic?

 

The Bentley lists it as the main engine harness connector, but I haven't found it on the wiring diagram because I can't find a connector number for it.