[shadowx360]

Hey, guys, I have a few questions regarding my 2006 330i. I recently bought it and I have a few questions.

First, where is my TCU module located? I have an issue with it and I can't seem to find it, all the online tutorials say under the trunk floor but my trunk floor is covered with this carpet-like layer and I can't seem to find where they could possibly stick a TCU module.

Second, I have these car parts in the trunk that I need someone to ID:

The black thing on the bottom has the words "BMW Safety Part. DO NOT REMOVE" and a BMW manufacture date on the back of it.

Third, while trying to look for the TCU, I opened this compartment that is on the left side (battery compartment is in the right side) of the trunk. Can someone tell me what this is? Judging by the metal fin design, it seems like an electrical component that would get a lot of heat, maybe an inverter?

Also, what is that wire that isn't hooked up to it? It's in some sort of wrap and is just lying there.

Thank you in advance.

[MGM]

Originally Posted by shadowx360

Hey, guys, I have a few questions regarding my 2006 330i. I recently bought it and I have a few questions.

First, where is my TCU module located? I have an issue with it and I can't seem to find it, all the online tutorials say under the trunk floor but my trunk floor is covered with this carpet-like layer and I can't seem to find where they could possibly stick a TCU module.

Second, I have these car parts in the trunk that I need someone to ID:

The black thing on the bottom has the words "BMW Safety Part. DO NOT REMOVE" and a BMW manufacture date on the back of it.

Third, while trying to look for the TCU, I opened this compartment that is on the left side (battery compartment is in the right side) of the trunk. Can someone tell me what this is? Judging by the metal fin design, it seems like an electrical component that would get a lot of heat, maybe an inverter?

Also, what is that wire that isn't hooked up to it? It's in some sort of wrap and is just lying there.

Thank you in advance.

What is the part # on the white label? Almost looks like an audio amp.

[shadowx360]

You are right. I checked the part number and it's an amp. Any idea what the other two are? I found the TCU under the cargo carpetting, to the right near the back seat

[Efthreeoh]

The other two are for the battery. The metal brace Holds down the battery for roll over protection (Part No. 1 in the first pic). The black Styrofoam (Part No. 11 in the 2nd pic) goes around the battery hold down bolt (Part No. 3) in the first pic.

[shadowx360]

Thanks for the reply, Efthreeoh! Do I really need those two parts in there? I am missing both bolts that hold the anti-roll bar in place and it seems to be pretty pricey for replacement. BMW says it's safety equipment and shouldn't be removed, but I'm not sure if it's worth it as I've never seen an instance where a battery needed anti-roll equipment.

[Efthreeoh]

Originally Posted by shadowx360

Thanks for the reply, Efthreeoh! Do I really need those two parts in there? I am missing both bolts that hold the anti-roll bar in place and it seems to be pretty pricey for replacement. BMW says it's safety equipment and shouldn't be removed, but I'm not sure if it's worth it as I've never seen an instance where a battery needed anti-roll equipment.

Well you have the parts already, except the bolts for the bracket. I'm curious as to why these parts were not remounted. I'd expect the battery has been replaced with a non-BMW battery that is not the correct fitment (and that brings up the whole battery registration issue). The "safety device" is the Styrofoam pad that fits in between the battery and the rear bulkhead of the car to protect the battery during a rear end collision. The hold down bracket holds down the battery more securely. All you are talking about are two bolts that are $.25 each from BMW, or just go to realoem.com and find the correct size bolts (M6x12 - Metric 6MM by 12 MM long) and get them at a hardware store.

[shadowx360]

Originally Posted by Efthreeoh

Well you have the parts already, except the bolts for the bracket. I'm curious as to why these parts were not remounted. I'd expect the battery has been replaced with a non-BMW battery that is not the correct fitment (and that brings up the whole battery registration issue). The "safety device" is the Styrofoam pad that fits in between the battery and the rear bulkhead of the car to protect the battery during a rear end collision. The hold down bracket holds down the battery more securely. All you are talking about are two bolts that are $.25 each from BMW, or just go to realoem.com and find the correct size bolts (M6x12 - Metric 6MM by 12 MM long) and get them at a hardware store.

It came with a BMW AGM battery, though it died on me a week after buying the car and I had it replaced even though the dealer thought it was fine. I figured out later that the issue was that the IBS module was not hooked up so it wasn't sending the message to the DME to kill off drainage when power got low. After I hooked it up, I checked for any battery resets/recodings and found none. I tried to message him yesterday and he never replied, probably meaning he was having battery problems.

Anyways, I'm missing parts 2-8 so I'll go place an order with realOEM, the stuff like the elbows you can't get elsewhere.

[Efthreeoh]

Originally Posted by shadowx360

It came with a BMW AGM battery, though it died on me a week after buying the car and I had it replaced even though the dealer thought it was fine. I figured out later that the issue was that the IBS module was not hooked up so it wasn't sending the message to the DME to kill off drainage when power got low. After I hooked it up, I checked for any battery resets/recodings and found none. I tried to message him yesterday and he never replied, probably meaning he was having battery problems.

Anyways, I'm missing parts 2-8 so I'll go place an order with realOEM, the stuff like the elbows you can't get elsewhere.

I'm not sure the lineage of your battery, but the OEM battery in the 330i was a white regular, flooded-cell, lead-acid battery, not an AGM. Whoever installed the replacement battery after the original one that came with the car from the factory, seems to not know what they were doing. I'd suspect the IBS is damaged (it is easily damaged) and that is what is causing your battery problems.

Attached is the TIS battery replacement procedure.

Hope all this helps. You can't order from real OEM.com but you can find all the part numbers and then order the parts on line. I use getBMWparts.com because they are a large stocking dealer and usually have most everything in stock or two-days shipment from BMW USA. Just get all the parts from them, or at least use all BMW OEM parts, the prices or not unreasonable.

[shadowx360]

Originally Posted by Efthreeoh

I'm not sure the lineage of your battery, but the OEM battery in the 330i was a white regular, flooded-cell, lead-acid battery, not an AGM. Whoever installed the replacement battery after the original one that came with the car from the factory, seems to not know what they were doing. I'd suspect the IBS is damaged (it is easily damaged) and that is what is causing your battery problems.

Attached is the TIS battery replacement procedure.

Hope all this helps. You can't order from real OEM.com but you can find all the part numbers and then order the parts on line. I use getBMWparts.com because they are a large stocking dealer and usually have most everything in stock or two-days shipment from BMW USA. Just get all the parts from them, or at least use all BMW OEM parts, the prices or not unreasonable.

Wow thanks for that info. I didn't realize the OEM battery isn't AGM. I fixed the IBS by connecting the CAN bus connector that wasn't connected. I now suspect previous owner changed battery at some indy shop that didn't know what they were doing judging by your info regarding the flooded cell battery. He probably also installed a battery with wrong specs because I purchased a replacement with those specs and it's not what the OEM specs are. My car apparently only needs a minimum of 650 CCA to crank but even with this 700 CCA one, crank is rough and hard. However, if I connect my car to a friend's car with jumper cables, crank is always smooth, probably either a voltage drop or a lack of amps issue. Either way, I'll go and put back in a factory 850 CCA battery in once I get the chance. Higher amps should reduce the voltage drop.