|
|
|
I know this topic comes up occasionally but thought I toss it out again. Has anyone succesfully repaired one of the so called failure prone ECU's. (561,556,572) Reason I ask is the spare 572 I bought for my LH3.1 245 at the yard today was DOA. The 561 can be replaced with a white label 561 or 951 and the 556 with either a 933 or 946 but is there an upgraded ECU for 3.1?
|
|
|
|
|
Why bother?
I have a rebuilt 561 in my car, and a used 951 in the other.
The 951 is more fun to drive. Now call me crazy, but I SWEAR on my life, that ECU is perkier. And this is after having it in both cars at different points.
|
|
|
|
|
"Why bother?"
I would like to have a spare ECU for my LH3.1 245 with a purple label 572. This is the vehicle I use for trips. It appears that all the problem prone ECU's(pink 561, yellow 556, purple 572) all have the same failure prone ceramic hybrid substrate. Finding a spare 572 is difficult. Finding a white label one even harder.
I have 3 spare 951's and 1 white label 561 and am willing to scarfice the white label 561 to try and repair the 572. I'm assuming the ceramic hybrid substrate from the white label 561 will work in the purple label 572. Time will tell. Its been awhile since I had the soldering iron on but I'm pretty sure I'm up for the job. Worse case is I ruin a working white label 561.
Was hoping Art B. would comment as I know he's done some comparisons of a pink and white label 561.
BTW: LH3.1 does run good.
|
|
|
|
|
Ah you have LH3.1, that's right.
|
|
|
|
|
FWIW -
There are other substitutions available for the 561 ECU - just don't want to let misinformation cloud the issue. I'm running a 933 in a formerly pink-labeled 561 1990 245 without trouble. I put together an ECU table that I'll be glad to revise if need be - Volvo LH ECU database.
Zach Zaletel
Anchorage, Alaska, U.S.A.
1990 245 w/256xxx mi
Pictures pictures pictures
|
|
|
|
|
For what its worth this is what I have in my table.
LH 2.4 0 280 000-561
LH 2.4 0 280 000-936
LH 2.4 0 280 000-951
LH 2.4 EGR 0 280 000-556
LH 2.4 EGR 0 280 000-933
LH 2.4 EGR 0 280 000-946
LH 2.4 TURBO EGR 0 280 000-560
LH 2.4 TURBO EGR 0 280 000-939
LH 2.4 TURBO EGR 0 280 000-937
0 280 000-954??
LH 2.4 TURBO 0 280 000-563
LH 2.4 TURBO 0 280 000-967
LH 2.4 TURBO 0 280 000-973
LH 2.4 16V 0 280 000-571
LH 2.4 16V 0 280 000-928
LH 3.1 0 280 000 572
|
|
|
|
|
Although the 933 and 946 do work in place of the 561 they are replacements for the 556 and have circuits to control the EGR system.
The 554, 544 and 541 are all interchangable for the LH 2.2 cars from 85-88.
Dan
|
|
|
|
|
I'll add those bits of information to help clarify for everyone.
Thanks-
Zach
|
|
|
|
|
Disclaimer: This is just my observations and opinion should not be taken as fact nor a recommendation to repair a ECU or consider instructions.
Yesterday I opened up a bad 556 as a practice session to trying to fix a bad 572. Doing some searching on older posts I came to the conclusion that pin 20 failing to energize its section of the fuel relay is the problem. In contrast to pin 20, pin 21 is driven by what looked to be a fairly large discrete transistor along with some zenner diode clamp protection.
pin 20 is driven by a dual layer 40-50 pin(didn't count) ceramic hybrid substrate with a fair amount of laser trimmed resistors and some surface mount capacitors. There is also 2 integrated circuits die bonded to the substrate. To me it looked like the driver for pin 20 is most likely on one of the IC's. If had to guess I would say that repeated voltage spiking on pin 20 could eventually damage the driver. Typically I would also say that the 2 IC's where fabricated on fairly low voltage process(20-30V) that would make them susceptible to damage.
Due to the rarity of a white label 572 I'm thinking of replacing the hybrid ceramic substrate with one from a more robust white label 561 donor.
|
|
|
|
|
Hello,
If the ECU is not sending a ground to the fuel pump relay indicating no tach signal you can try a work around. Add a K-Jet fuel pump relay that operates from a tach signal off the coil. Use the contacts on the relay to supply ground to the existing relay. This keeps the no run fuel shut off in place with the existing ECU. Total cost about 35$ and a connector from a junk car.
Mario
--
82 242 DL-MPG
|
|
|
|
|
Yama:
Sorry, pageda is correct, no alternate and they are rare as hens teeth. Last one cost me $125 untested, no guarantee. I got lucky, its a good one.
I'm in the process of doing a B230F+LT conversion, once installed and running, I'll have one spare 572 left (the other is promised to another project), but I will have one left. Contact me off line if you are interested, I will hold it for you once the conversion is done. Note, this won't be a quick conversion, 2 to 3 months is the estimate and in the meantime, that 572 is in my DD.
jorrell
--
92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!
|
|
|
|
|
Jorrell,
I was hoping you could tell me what component to change. Didn't Art B. sketch out the circuit?
|
|
|
|
|
Yama:
Sorry, don't recall the Art B. post on that one but I will look for it... since its Art B. I know it is accurate. The dead one I got my hands on had a failed regulator (shorted)input to output, so the processor and memory were smoked... yep, took out the fuse, the microprocessor package was split and there was remnant oil on it... where the smoke came out. The electrolytic caps were not to blame on this one.
If I may ask, when you plug in the DOA, does the fuse pop? If I recall correctly the 572 has a 28 pin EPROM, pin 14 should be ground, 28 should be 5V (if it is a 24 pin, pin 12 is ground and 24 is 5V). If you measure 5V +/-10% the regulator is good. If you get zero Volts or something below 4.5V, track the traces back to the regulator. NOTE: Very fuzzy memory on my part here, so if the EPROM has a part number on it, pull up the datasheet via a Google search to validate the power and ground connections. I'm pretty sure that the EPROM was a 5V only part in the 572 and NOT a 5V, 12V, -12V part!
If the fuse is popping, follow the power feed until you find the short, you know, the ol' lift one power pin at a time until the short disappears. Caps and clamp devices are the most common culprits. It doesn't hurt to look for overheated traces on the board either or hot parts before the fuse blows.
Sorry that I don't have the details on this one, but I haven't dug into the 572 that far on the hardware side. I might be able to dig up the processor pin out though if you need it... NOT the Bosch programmed pinout, but the Siemens bare unprogrammed part pinout. One last question, is dead ECU capable of throwing a code, even a 1-1-1? The reason I ask is that a 1-1-1 at least tells you that the power system and the core processor/memory is good.
Good luck and let us know what you find, I'll help out where I can! If the ECU powers up and "runs" I might be able to hook up the in-circuit-emulator (ICE) and see what is going on. NOTE: the ICE I have is almost 20 years old so flaky results should not be ruled out.
jorrell
--
92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!
|
|
|
|
|
Jorrell,
No fuses popped when the bad 572 was plugged in. Your problem with a 572 seems more of a rare situation than the more common issue with the fuel relay driver on the ECU. Either pin 21 or 20 or both fail to provide a low level to energize the fuel relay. This is the problem I had with a bad 556 and what I suspect is wrong with the 572. I guess I'll open one up and see if I can trace back pin 20,21.
|
|
|
|
|
hello
i never heard of a upgrade for the 572, and they are pretty hard to come by.
i have only found three in five years of constant JY visits.
good luck
mike
--
95 944T, 94 945T, 85 244T.
|
|
|
|
|
I hardly ever see them either. This was the 2nd I've seen in around the same time. Figured I take a chance. Now I know why that 245 was junked.
|
|
|
|
|
Yama:
Agreed, a bad 572 will eat your wallet alive, but at least a brand spanking new Bosch LH 3.1 AMM only runs $100 vs. the bend-over price of a LH-2.4 unit! Also don't forget that the LH 3.1 system has spared you of having to deal with a leaking cold start injector and a "twitchy" throttle position switch (replaced by a non-adjustable throttle position sensor).
Just trying to lighten your LH-3.1 opinion at this point. Unfortunately, Ebay seems to be fresh out of the 572 right now... I'll keep my eyes open.
--
92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!
|
|
|
|
|
Have you actually seen a white label one. The 2 I have are purple labels.
|
|
|
|
|
Yes I have seen one. Here are Art's links to pictures that show the good and bad circuit boards for the 561 but I don't recall if he actually repaired one. I'm sure Art will ring in on this one. Dan
http://cleanflametrap.com/561-bad.jpg
http://cleanflametrap.com/561-good.jpg
|
|
|
|
|
