ECU #153

[mph]

How do I open a 153 ECU? There are 4 larger screws and 2 smaller ones: I removed both. There are also two plastic tabs that can be pulled out: I pulled those out. I can't find out how the ECU opens up.

Does the black internal part pull out from the aluminum case, or does the one side of the case pull off?

It's a 153 ECU from a 1986 325iC, Euro (not sure if it makes a difference with years and what not. Any ECU 153 should be the same.

Anyone have any ideas?

[rs4pro3]

On the 153 I had you had to bend up the metal tabs on the cover and pull the cover off the main board then seperate the two boards to get to the chip.

[mph]

Thanks. I figured it out, but it's a huge pain in the ass compared to the other ECU's.

[fporro]

try to find a 173, it will idle a lot better :)
straight swap from 1.1 to 1.3 motronic, perfect upgrade on my 87 325ic :)

[Low Level E30]

What's the difference between a #153 and a #173?

Obviously the #173 is newer......

.... so how is it -better- ?

[fporro]

# 173 gives better idleing and somewhat smoother reving. you still get a good kick at 3500 rpms.

as per fault codes, it flashes more of them than 1.1 motronic units. so it's easier to pinpoint trouble.

swaping chips it's easier too :)

[bimmerphile]

If you replace the whole ECU, can you put a 173 ECU in a 153 car?

[fporro]

yeap, that;'s what i did on my 87 325ic.
the 153 started to fail, car would hesitate at w.o.t. between 32 to 3500 rps, sometimes it was truble free fopr a few days then go in a binge.

swaped countless parts, like fpr, fuel flter, maf, cap, rotor, plugs, pts, and who knows what elese.

eventually found a 173 at local yard, in she went and g'by to troubles a waived :)
# 173 has a 3rd row of pins, that's ok, if you look at yoir harness you'll see a 3rd row as well.

[mph]

Well, it might just be a good time to upgrade ECU's. I broke one of the resistors when I went to put the chip in. Now the ECU makes a low pitched humming noise.

[jtuner]

Sooo... I was running a 021 ecu in my 325e.. i switched to the 027 ecu and don't see much difference.. Would i be able to put a 173 in my car? This seems to be the best ecu all around wherever i look...

[Fred]

Sooo... I was running a 021 ecu in my 325e.. i switched to the 027 ecu and don't see much difference.. Would i be able to put a 173 in my car? This seems to be the best ecu all around wherever i look...

No. The 153 is Motronic 1.1, the 173 (and higher) is Motronic 1.3, which why it is an upgrade for 325i's. Both the 021 and 027 ECUs are Motronic 1.0 (and have no real difference, besides the 027 has a detachable chip and the 021 is soldered) and are not compatible with different versions of Motronic; if you compare the pins, the eta has a two row connector while 325i's have a three row.

[jtuner]

ahhh ok cool.. i figured it wouldn't work since nothing else fits on the 'e' that fits on the 'i's :) Thanks for the info.. guess best I could do for this car is the chipped 027.. Unless i get this ix, then it's open forum for me once again :)

[cyrmanj]

can you put a 173 ECU in a 153 car

This means that 153 chips (like a Dinan for example) works fine on a 173 ECU? If that is true why are they advertised differently?

Thanks

[lordofthewaters]

This means that 153 chips (like a Dinan for example) works fine on a 173 ECU? If that is true why are they advertised differently?

Thanks

No. 153 chips work ony in 153 dmes. The 380 can use 173 chips and vice versa however.

[everlast]

My '88 "i" started a lot easier with the 173 upgrade. Also gives you the ability to do the "stomp" test for Check Engine Light. The 153 only has a limited number of codes.