IX ECU question

[GT BMW E30]

I have a 90 auto IX with a 351 ECU. Engine light is on for O2 relay. I traced the issue to the ECU #23 pin. Is a 153 ECU from a 325ic manual compatible?

[flyboyx]

the ix ecu has a feature that actuates the icv in certain instances to keep the wheels from sliding when you are on ice and the throttle is closed(or something like that)

if i were you, i would use an ix ecu.

also, go somewhere and get a smoke test on your intake system. more than likely you have an intake leak. perhaps the gasket between the intake manifold and the head.

it is unlikely the culprit is actually the engine module for that issue.

[GT BMW E30]

Its not the intake. Its the ECU because I am not getting a signal from the wire. It seems like One of the previous owners disregarded changing the O2 sensor when light came on. It burnt out the wire,relay and the pin to ECU. I had a known BMW E30 mechanic check it out and I had my father double check it. For now I spliced in another wire.

When I bought car it was the only issue. I thought i would just have to swap in a new O2 sensor. I bought a used complete harness to swap over.

the ix ecu has a feature that actuates the icv in certain instances to keep the wheels from sliding when you are on ice and the throttle is closed(or something like that)

if i were you, i would use an ix ecu.

also, go somewhere and get a smoke test on your intake system. more than likely you have an intake leak. perhaps the gasket between the intake manifold and the head.

it is unlikely the culprit is actually the engine module for that issue.

[GT BMW E30]

just found this on another forum. it seems i have a few options. Does anyone know if the 524 has more updates than the 173?

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 173
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 351
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 380
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 382
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 524
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 525
Bosch Motronic M1.3

325i/is/iX
E30
M20/B25 (170hp)
87-91
0 261 200 526
Bosch Motronic M1.3

[nando]

The ix ecu is not unique. There is in fact no such thing as an "ix" ecu - all motronic m20b25 computers have the circuitry for opening the ICV based on ABS input.

All motronic 153 ecus have the same code, they came in many models including the ix. A 325ic dme will work fine. Although, i would recommend finding a 173 or later computer. There were actually some issues with the 153 in earlier ix's causing ABS faults.

the DMEs all basically have the same tune. the later ones (524, 525, and 526) have a speed governor set at 125mph.

[TobyB]

the later ones (524, 525, and 526) have a speed governor set at 125mph.

This is true.

t

[dnguyen1963]

This is true.

t

Yeah, but where can you drive around here with this kind of speed?

[nando]

125+ is quite easy on a racetrack

[GT BMW E30]

IX will be a daily driver so I will not be driving 125 mph. Also can upgradable chips remove the governor anyway?

[flyboyx]

The ix ecu is not unique. There is in fact no such thing as an "ix" ecu - all motronic m20b25 computers have the circuitry for opening the ICV based on ABS input.

All motronic 153 ecus have the same code, they came in many models including the ix. A 325ic dme will work fine. Although, i would recommend finding a 173 or later computer. There were actually some issues with the 153 in earlier ix's causing ABS faults.

the DMEs all basically have the same tune. the later ones (524, 525, and 526) have a speed governor set at 125mph.

really? ive had the cover of several e30 ecu's. the ix units have two circuit boards sandwiched on top of each other. any standard i brain box has only one. i can't say what that means since i'm no computer guru, but i'm pretty sure there ought to be some difference since they came with different units and different part numbers

[Andy.B]

really? ive had the cover of several e30 ecu's. the ix units have two circuit boards sandwiched on top of each other. any standard i brain box has only one. i can't say what that means since i'm no computer guru, but i'm pretty sure there ought to be some difference since they came with different units and different part numbers

153 dme's have two boards, while 173 and newer dme's have one board.

[nando]

really? ive had the cover of several e30 ecu's. the ix units have two circuit boards sandwiched on top of each other. any standard i brain box has only one. i can't say what that means since i'm no computer guru, but i'm pretty sure there ought to be some difference since they came with different units and different part numbers

those are early 1.1 DMEs. they're still compatible with the ix - FYI my parts car came with a dual layer Motronic 153. :)

operationally they're the same, although much more prone to faults since they are so much more complex.

[TobyB]

Also can upgradable chips remove the governor anyway?

Didn't on my 524.

About 50 yards from turn- in at T1 at Pacific, thing just died.
I'd have to scrub off maybe 5 mph to get it to come back.
Then it'd come back.

t

[GT BMW E30]

UPDATE: I replaced 153 with a 524. Big difference in idle and trans shifts. Very happy.

My check engine light is still on for O2 sensor circuit and O2 sensor heater relay.
I have checked the relay (good), brand new O2 sensor and circuit for signals (brn/grn wire to ecu no signal). I spliced my harness brn/grn wire with new wire. Light came on. Then I replaced the ecu. Light came back on. I have a spare obdII wire harness that I am going to install. I read the obdII harness is confined so I hope this resolves the issue

[usualdeviant]

Can someone explain to me why I replaced my 153 with a 524 and it has a code for a vehicle speed sensor signal? I mean I would think that DME uses the signal but my harness does not supply it to the DME. So is it really compatible? 1987 325i.