Hello folks, Yes I am new to this very informative site and I have a question to ask. My 740 Volvo has a Bosch ECU 0280 000 561. What other numbered ECU's are compatible with this one as I have found several with ending numbers 541 and 511 but none with 561. Can these work????
Or possibly does anyone have one that they can sell me?

 

I forgot to include year.... Its a 1989 Volvo 740

 

933,935,951, and of course a 561. A 541 is for LH 2.2,yours is a LH 2.4 I've never seen a 511.The 561 is a good ecu,are you sure yours is bad?



Dan

 

Hello Dan,

My "madchanic" thinks its the ECU not functioning because we changed the intank and out side fuel pumps and to no avail.... we are not getting any current to the pumps. I told him to check the relays and he said he did. So would you think it is the ECU malfunctioning???

Alvin

 

Alvin, you may very well need an ecu...eBay is the cheapest place to get one. BUT...your mechanic may not know Bricks very well...the fuel pump relay fails quite often. If there is no current to the pumps, any reputable tech will start tracing back to where the juice stops. Your car has OBD...did your tech read the trouble codes?

 

After I answered your question yesterday,I happened to remember that ecu doe's have problems.This is assuming it has been properly diagnosed.


Dan

Here's the C/P

561 ECU Workaround: Swap the Relay and Not the ECU. [Tip from Colin ] It has been suggested that it may be possible to overcome the failure of the 561 ECU to operate the fuel pump relay by replacing the (white) L-Jet relay with the (green) K-Jet relay. This type of relay senses engine rotation internally instead of using the ECU. The relay fits the same relay base as the (white) L-Jet one but is wired differently. Reading my latest edition of the UK. V.O.C Technical Driver magazine I found an article by Peter Suchy on how to do just this. With the permission of Jack Cluer (the editor) I have reproduced the relevant part below. First remove fuse one! Then remove the wires from the fuse/relay unit, with a slim spike pushed down between the housing and connector release the barb then push the connector out, you will need to bend the barb back out so that it locks when you refit the connector. Then put them back as follows making sure they correspond with the numbers on the relay thick blue/yellow wire to 87b,pink to87, brown to 30. Run a (blue/red) wire from terminal 15 to to fuse 13. (an ignition controlled source) Run a ground (black) wire from the negative bus on the fuse box to 31 Run a (red/white) wire from the single Red/white wire on the tach to terminal 31b. You will now be left with the black/yellow, red and a looped blue/yellow and brown and white wires. Insulate these and tie them neatly away in the loom where they can accessed if needed. Tape the wire from the instrument panel firmly to the loom and make sure that all wires are neatly fitted. This is to prevent the wires pulling out next time you remove the fuse box! Now refit the relay making sure all the connectors are firmly pushed into the relay base and start the engine! The relay is now powered by an ignition pulse from the coil when the engine is turned over. The above is a bit more work than fitting a new ECU but a hell of a lot cheaper and it retains the original safety feature of cutting off the fuel supply if engine rotation ceases.

 

Now that is a great work around! My concern is just how much diagnosis was done to this man's car. Apparently the fuel pumps weren't running so the tech replaced 2 pumps? Still doesn't run so now it's the ecu? Sheez, throw enough parts at it, it'll get fixed eventually. If there wasn't any current going to the pumps BEFORE they were replaced why would one think electricity would magically reappear with the installation of new pumps? I realize not every shop has AutoForce scanners (they are very old school) but I'm sure the tech has access to a test light. Replacing both pumps, including draining and refilling the gas tank is close to 4 hours according to AllData. At our shop, with parts...you're looking at $600-700. And the car still doesn't run? Maybe I'm being harsh, but if it were my car, it would be heading for another shop.

 

Yes, we may have to go step by step the long way. Good thing my madchanic doesnt charge me until car is up and running.....Would you think to change the Hall Effect Sensor in the distributor ( or do I even have one ), remember I have the LH 2.4 electronics, or does it carry the RPM sensor over the bellhousing??? Also would the ICU ( Ignition Control Unit) be the culprit as well???

Thanks for all you help....

 

Has the guy tried jumping the relay between pins 30 & 87/2? Or checking for voltage on the correct pin off the ecu? If you're fairly electonically savvy and it turns out to be the ECU you can repair the fuel pump control circuit. Also I hope the guy has the EZK plugged in.

Anyways I have a 561 if you want to buy it.