C900 ECU Identification - or Scandinavian Roulette!

[SteveI]

I have an ECU with no external markings and need find it's part number.

It's a Bosch 25 pin from I think a 88-89 16v turbo.

Apart from a green circular sticker next to the label where the part number should be - (looks like someones cleaned it off with a slovent so I have the silver sticker now less the blue background and part details), there are no other markings but a stamped '447' in the aluminum case by the top right mounting hole).

So is it safe / worth breaking in to see if there are any identifying numbers inside / on an EEPROM or such or an I'm going to play ECU roulette.

I have an accompanying MAF ending in 005 and injectors 280150712.

The loom plug does not have the pin connectors for a lambda / O2 sensor if that helps.

Thanks.

[euromobile900]

You can probably use any LH 2.2 ECU from a non-lambda turbo car, to replace yours. Should work passably. Here's a table with the different ECU and injector and fuel pressure regulator and air-mass meter part numbers for LH 2.2 900 cars without catalytic converters (thus without lambda). This should help you narrow it down. Just don't take an ECU from a 9000 or a car with a different MAF or fuel pressure regulator. It won't work (well). I don't think putting in the wrong ECU will hurt anything, it just may not run right.

Looks like, from the table, that your ECU is the -547, and, at first blush, it seems it's the only one that will work, because it's the only one that goes with a -005 MAF and a 2.8 bar FPR. If you couldn't find one, you could always replace the MAF or FPR as well. The footnote for the -017 MAF is that it's plastic, but still adjustable like the -005 metal one.

Car	Year	Motor	Trans		Fuel Pressure Regulator			Mass Air Flow Sensor		Injector		ECU
			Manual	Auto	Bar	Bosch	Saab	Bosch	Saab	Bosch
900	1984	B202L	X		2.5	-214	75 01 646	-005	93 75 643	-706	75 09 862	-517	75 14 904
900	1985	B202L	X	X	2.5	-214	75 01 646	-005	93 75 643	-706	75 09 862	-521	75 26 114
900	1986	B202L	X		2.5	-255	75 64 131	-005	93 75 643	-706	75 09 862	-533	75 29 092
900	1987-8	B202L	X		2.8	-264	75 68 041	-005	93 75 643	-712	75 60 170	-547	75 36 683
900	1989	B202L	X		2.8	-264	75 68 041	-017†	89 78 280	-761	74 87 010	-569	74 87 119
900	1986-	B202L	X		3.0	-256	75 64 123	-017	89 78 280	-760	74 87 028	-573	91 14 703
900	1986-	B202L		X	3.0	-256	75 64 123	-017	89 78 280	-760	74 87 028	-568	89 75 443

[SteveI]

Thanks Sam..been looking for a chart like that for days now. Thanks for the guidance on the ECU too..I'll post back once I have her running.

SteveI

[SteveI]

She's been running fine for 4 months and done 4000 miles without a hitch other than running a bit rich but I never had the CO2 adjusted and left the AMM at 380ohms ....2 days before the annual inspection she started running like a *******. Failed the emission check on massive hydro carbons i.e running way, way to rich all of a sudden.

I've cleaned all the earths, re buzzed out all the wiring and checked the AMM resistance, NTC resistance from room temp to plus 80 and the TPS...all appear to be fine. I'm down to my last AMM -005 which doesn't look to be in good shape.......back to the thread.

I finally got around to identifying my ECU.....carefully bend back the 6 tabs on the aluminium cover and lift the cover off...hey presto a green label on the circuit board reading 0 230 000 517 which means not only is she mysteriously running like a ******* but I have the wrong FPR and injectors........maybe I just scrap the whole project and by a 9-3.

[peva]

Hate to throw a spanner in the mix. You don't state the year of your 900 but a lot of UK turbos has Lucas ECU not Bosch. Does it have a gold block bolted to the bulkhead near the PAS reservoir. This identifies a Lucas.sss

[SteveI]

You know that Johnny Cash song -about a car assembled from a miriade of other models............so ''one piece at a time'' it's been variously an 900i 8V, 900T 8V, 900T 8V with T16S intercooler....then jumped from CIS to LH2.2 on a un known year engine and loom bought as a job lot...but the ECU had no external markings and I didn't want to crack the case off......one piece at a time and it really has cost me a dime (loads of 'em)......thinking of going T5 one day but need to get the LH running first just cos I'm so stubborn!