1994 Volvo 850, no spark, ECU??

donCorleone · Post by **donCorleone** » 11 Oct 2018, 13:06

Hello Mates,
I have a 1994 Volvo 850 wagon, non-turbo with no spark. I did what anyone might do down the line of normal tune-up items (wires, plugs, filters, cap, rotor, etc,) and on to both the cam and crank sensors. Still no spark, time to go to a local volvo specialist. He has thrown in the towel, cannot figure it out, even after supposedly having tried an ECU (not Ingition CU, though i have now changed that as well) and have since brought to another shop. They believe it is 99% narrowed down to the ECU, and none of us can find one with matching numbers. There is the general bosch type number, then on vertical side, 4 sets of numbers...do all these sets need to match for it to perform? Is it simple plug and play for this year (no need for computer re-prog?)? Any ideas on where to find one of these to match or any other topic are welcome. The 4 number sets I have been told need to match and am looking for are P09146476, 1T28S2395, CP101, T93440290.
Probably more for a classified ad, but this car is currently for sale in condition and/or after repaired, 166K wagon w/sunroof, 5 speed manual.
Yes, I have checked eBay and multiple sites, none have those numbers. I am even willing to upgrade it if that makes it run again.

Post by **RickHaleParker** » 11 Oct 2018, 23:31

One thing not on your list of things is ignition coil ....

donCorleone · Post by **donCorleone** » 12 Oct 2018, 08:09

My apologies, I should have been more thorough when I noted general tune-up items.
Yes sir, I did the coil also.

Post by **RickHaleParker** » 12 Oct 2018, 11:23

Does this car have a OBD under the hood?

Engine speed sensor or the loom to it, can cause a no spark.

37b = Engine speed sensor.

donCorleone · Post by **donCorleone** » 12 Oct 2018, 12:36

Hello Rick,
Thanks for additional thoughts. I believe the part you refer to (37B) is what may also be referred to as the camshaft sensor, if so, then Yes, that has been done (pic looks exactly like and location of the cam sensor I changed).
OBD....just in front of the box that houses the ECU and ICU are two ports, OBD-ish looking early type things, much lager pins (8-10mm) that a local technician told me is an early diagnostic readout but that to get a computer to read it is near impossible to find.

greg850r · Post by **greg850r** » 12 Oct 2018, 12:48

https://www.matthewsvolvosite.com/read-codes-volvo-850

Post by **misha** » 12 Oct 2018, 12:58

Never go back to him again.

Your OBDI system require ONLY pencil and a piece of paper to write down flash codes...system have it's own diagnostic ports.
There is no possibillity to use any scan tool or computer software on this OBDI system.

donCorleone · Post by **donCorleone** » 12 Oct 2018, 14:43

Greg and Misha, thanks for insight...it actually jogged my memory, tech told me not about computer connecting to it, but that when pushing the button on it, it does not activate flash or send code, as if it is shot/bad bulb/new england corrosion/etc. Sorry for the inaccuracy in post. Another technician told me that getting a breakout box to get more specific tracking from the ECU pins was near impossible to find. This breakdown of the 850 has been such a cluster of chaos that my head has not stopped spinning.
Meantime,2 local junkyards told me they found ECUs. One has matching numbers, the other does not. Are the number sets in my first post crucial to be an exact match? It seems almost 99% indicative of the ECU in several peoples minds...is it worth a non-returnable 150 $ part? Cause if that does not fix it, my patience will be depleted and the car likely to scrapyard.
Below is what mine looks like.
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donCorleone · Post by **donCorleone** » 12 Oct 2018, 14:45

Sorry, here is the pic...I hope

Post by **misha** » 12 Oct 2018, 15:11

Check all fuses in the fuse box and proceed with instructions greg850r allready posted.
Diagnostics on these OBDI cars are pretty easy,just make sure that key is in position II before starting procedure.