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Old 08-18-2020, 10:56 AM   #1
taylor84240harris
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Default Code 144 91 240

I’m getting a 144 code on my 91 240 and I’ve read several threads that I could find and none of the suggested fixes have really made a difference in my particular scenario. Things like Ingition System Relay, Injection System Relay, Radio Suppression Relay, Crank Position Sensor, bad ECU, bad ICU and so on. I’ve replaced the cas with a known good one and checked all of my vacuum hoses. The car seems to just have a high idle and pour fuel consumption. I know 240s don’t have the greatest fuel mileage but this seems especially bad. I read also that the code can cause intermittent stall issues which I have an experienced at all yet. I’m afraid I may have a bad computer but not really sure how to test that.

Thanks in advance
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Old 08-18-2020, 12:25 PM   #2
283SD
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Code 144; EZ-116K fault codes. Load signal missing[from LH control unit]. Control unit assumes the engine is at full load.
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Old 09-02-2020, 12:05 PM   #3
taylor84240harris
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I performed continuity test between ECU pin 25 and ICU pin 8 and it checks out. I also Checked The ground between ecu 25 and 17 and got an infinite ohm reading. One thing that is curious is in my research I e found that the ecu 556 is coming up a lot with this code. It’s a California emissions ecu. Short of just replacing the ecu with a known good replacement or substitute like 936, 954, or 967, is there anything else I can look at as the cause?
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Old 10-13-2020, 01:50 PM   #4
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Alright still hunting the cause for code 144, now I’m also getting code 131, missing or faulty rpm signal. I have confirmed the cas is good and I have a new power stage installed. I’m sure these codes are related I just need a little nudge in the right direction. Only symptoms I’m getting are high idle and hunting on startup which I’m thinking is the missing rpm signal. Most of what I’m reading people with these codes cars don’t run will not start or die after warmed up. I’m not having any of those issues. Any ideas?
Thanks
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Old 10-13-2020, 02:03 PM   #5
2manyturbos
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Mystery codes are often caused by a bad ECU. Borrow a 933 or 946 ECU and see if all the codes suddenly disappear. The 954 and 967 are Turbo ECUs. Not a suitable replacement for your 556.
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Old 10-14-2020, 08:48 AM   #6
taylor84240harris
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It’s pretty much the only conclusion I’m left with so thanks for confirming it. I found a 946 on eBay and it’s on the way. I also found these databases that list suitable replacements for most ecu’s. They both list the 954 and 967 as possible replacements for the 556 which is a California spec with egr. Not sure what makes it strictly for California emissions or if that would effect what computers I can use. Thanks for the help
http://www.nuceng.ca/bill/volvo/database/ecu.htm
https://www.volvoclub.org.uk/faq/EngineFIComputer.html
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Old 10-14-2020, 11:26 AM   #7
ZVOLV
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I fixed that code on my 1990 240. I think it was a corroded fuse holder by the battery.

Another member just fixed that same code by replacing the LH/Fuel pump relay. It powers the computers.
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Old 10-14-2020, 04:11 PM   #8
2manyturbos
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Quote:
Originally Posted by taylor84240harris View Post
It’s pretty much the only conclusion I’m left with so thanks for confirming it. I found a 946 on eBay and it’s on the way. I also found these databases that list suitable replacements for most ecu’s. They both list the 954 and 967 as possible replacements for the 556 which is a California spec with egr. Not sure what makes it strictly for California emissions or if that would effect what computers I can use. Thanks for the help
http://www.nuceng.ca/bill/volvo/database/ecu.htm
https://www.volvoclub.org.uk/faq/EngineFIComputer.html
I'm familiar with that table and it is full of mistakes. The 933 is an NA ECU, not a turbo ECU. I don't buy that conclusion on those being an acceptable interchange for the 556. Every computer on the list as an acceptable replacement are Turbo ECUs. Whoever compiled that list messed up. The suitable replacements are a 933, 946 and 951. Those are all NA computers that are much more reliable than the 556. The 556 is well known by long time Volvo shops/techs as a questionable ECU. They are known for false codes and driveability issues that you can't find the root cause of. That's because the ECU can't determine it is the part that is "sick". I'm not saying that is what is going on in your case. I'm just letting you know it is well known that the 556 is known for these issues. All the 5XX series ECUs are questionable. By the time Volvo developed the 9XX series of ECUs they created a very reliable platform. You pretty much have to do something negligent and damage one in order for it not to work properly.

If you want an ECU that is the direct replacement and an upgrade for the 556 you want a 933 or a 946. The 946 being the best US NA ECU with EGR. The EGR system is actually controlled by the EZK, not the ECU. That said, Volvo definitely paired different ECUs with the EGR equipped EZKs. There has to be a reason for that, though, nobody has ever figured out why as far as I have seen.

Last edited by 2manyturbos; 10-14-2020 at 04:17 PM..
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Old 10-17-2020, 03:03 PM   #9
taylor84240harris
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Got my 946 computer installed and everything seems to be as it should idle is spot on and no cel. Put about 100 miles on it and I believe it’s fixed. The 556 was apparently faulty. Thanks for all the help and getting me the correct info!
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Old 10-17-2020, 03:19 PM   #10
2manyturbos
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I'm glad you got it working correctly.
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Old 10-19-2020, 12:18 PM   #11
taylor84240harris
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Quote:
Originally Posted by ZVOLV View Post
I fixed that code on my 1990 240. I think it was a corroded fuse holder by the battery.

Another member just fixed that same code by replacing the LH/Fuel pump relay. It powers the computers.
Where is this fuse holder? All i can see by the battery is the power stage, highbeam relay, and power distobution block. I wanted to take a look at it to make sure it looks okay.
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Old 10-19-2020, 12:52 PM   #12
ZVOLV
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Good to hear you got it fixed.

1991 may not have that fuse. 1990 and back should.

I still recommend cleaning up the cabin fuses. They are a known weak point.
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Old 10-19-2020, 01:45 PM   #13
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Quote:
Originally Posted by taylor84240harris View Post
Where is this fuse holder? All i can see by the battery is the power stage, highbeam relay, and power distobution block. I wanted to take a look at it to make sure it looks okay.
1991 was the year it was eliminated.
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