96 N/A auto and 96 N/A 5sp ECUs interchangeable?

Post by **SonicAdventure** » 17 Aug 2020, 10:25

Hi, I snagged the ECU out of a 96 N/A 5sp the other day thinking it would fit in my 96 N/A auto. The engine VIN codes for both cars are 55, and the emissions VIN code for both cars is 4.

Are these interchangeable based on part number and VIN code match alone? Or, does the unit from a 5sp or Auto have additional internal components that would make them not work in this application? See photos.

Interestingly, the 5sp's chassis tag says "Made in Sweden" while the auto is marked "Made in Belgium" - was this based on trans unit the car shipped with or is this unrelated?

Post by **abscate** » 17 Aug 2020, 11:05

Two main factories for Volvo in EU are Ghent and Upsala - lacking umlauts...I think factory choice is model driven.

Post by **misha** » 17 Aug 2020, 11:36

Generally,ecu(s) are not interchangeable because of software differences.
The car will run with it,but not properly.
Transmission will not shift properly because look up table for auto trans is missing...orange arrow will be ON,idle will not be adequate...and you will be risking to ruin your auto transmission.

Looking up at the labels on both ecu(s)...it's interesting that they have the same software.
Are you sure that it came from a manual car?

But...looking at notes written with a pencil....there is possibillity that it is flashed and have a different software installed.

Post by **SonicAdventure** » 17 Aug 2020, 11:49

misha wrote: ↑17 Aug 2020, 11:36 Generally,ecu(s) are not interchangeable because of software differences.
The car will run with it,but not properly.
Transmission will not shift properly because look up table for auto trans is missing...orange arrow will be ON,idle will not be adequate...and you will be risking to ruin your auto transmission.

Looking up at the labels on both ecu(s)...it's interesting that they have the same software.
Are you sure that it came from a manual car?

But...looking at notes written with a pencil....there is possibillity that it is flashed and have a different software installed.

Yes the car def. had a manual trans in it at the junkyard, but the VIN indicates auto. Maybe the manual was a swap? Here is the VIN: YV1LS5540T1310271. If you google "Volvo YV1LS5540T1310271", images will pop up showing the car at the salvage auction. It def. had a manual transmission in it.

Post by **misha** » 17 Aug 2020, 12:40

...and maybe was flashed after a manual swap.
You can't know for sure...but notes on it could mean that it had manual software installed.

Try it....with key in pos.II you should have flashing arrow....if not....it isn't flashed.

Post by **SonicAdventure** » 18 Aug 2020, 14:39

misha wrote: ↑17 Aug 2020, 12:40 ...and maybe was flashed after a manual swap.
You can't know for sure...but notes on it could mean that it had manual software installed.

Try it....with key in pos.II you should have flashing arrow....if not....it isn't flashed.

Is there any special protocol for changing out an ECU? I’m thinking the negative cable should be removed prior to the swap.

Post by **erikv11** » 18 Aug 2020, 14:59

I've swapped them in and out without disconnecting anything. But you'll never go wrong disconnecting the negative cable, wouldn't hurt.

Post by **misha** » 18 Aug 2020, 15:03

Not necessarily....after you remove the key from ignition....just wait around 10-15 minutes for main injection relay to go in sleep mode(to click off).

Post by **FLXC90** » 18 Aug 2020, 15:51

Unless it's in the emissions description, where in the VIN do you see automatic transmission? Are you checking VIDA or another official Volvo database, because as far as I know, the VIN doesn't differentiate that. Otherwise, we could ID these in ads or on websites without having to scour junkyards looking. Don't take this wrong, I may be ignorant-It has happened before!!

I see YV1LS, Volvo 850 sedan, 55, Naturally aspirated 2.4L, 4 = w/o EGR w/air pump, w/OBDII, w/elec. control evap,Motronic 4.4 w/Rulo., TLEV (55), 0, which is a check figure, T = 1996, 1 = Torslanda, Sweden, then the car serial number.

Also there IS a different code set on the ECU labels, 0100 0822 vs 0100 0778, but I don't know if that is a data load, or what those symbolize.

As you have been warned, no they (Auto vs Manual ECUs) do not match in functions, RPM hang during shifts, speed sensor matchup, ECU will look for specific signals from TCU on Auto, or not if Manual.

EDIT: forgive rant, I saw what you saw at an "Official Volvo" site. But is this just because they have a database?

Post by **SonicAdventure** » 18 Aug 2020, 23:46

FLXC90 wrote: ↑18 Aug 2020, 15:51 Unless it's in the emissions description, where in the VIN do you see automatic transmission? Are you checking VIDA or another official Volvo database, because as far as I know, the VIN doesn't differentiate that. Otherwise, we could ID these in ads or on websites without having to scour junkyards looking. Don't take this wrong, I may be ignorant-It has happened before!!

I see YV1LS, Volvo 850 sedan, 55, Naturally aspirated 2.4L, 4 = w/o EGR w/air pump, w/OBDII, w/elec. control evap,Motronic 4.4 w/Rulo., TLEV (55), 0, which is a check figure, T = 1996, 1 = Torslanda, Sweden, then the car serial number.

Also there IS a different code set on the ECU labels, 0100 0822 vs 0100 0778, but I don't know if that is a data load, or what those symbolize.

As you have been warned, no they (Auto vs Manual ECUs) do not match in functions, RPM hang during shifts, speed sensor matchup, ECU will look for specific signals from TCU on Auto, or not if Manual.

EDIT: forgive rant, I saw what you saw at an "Official Volvo" site. But is this just because they have a database?

The auction listing was the only place that I saw the automatic, and that's highly likely to be just a mistake. The 55 engine code could be for auto or manual according to the checker I saw at new.volvocars.com. I also saw that different set of numbers on the label, but I still think I want to at least swap it out with mine and do like Misha said and put the key to II and see if the arrow flashes. DO you think there would be any harm in that? If the arrow flashes, I obviously won't drive it.

I wish there was a way to know for sure what the car left the factory with. Out of curiosity, I looked up several other salvage 96 850 sedans trying to see if there was a way we could tell by listed GVWR. However, it looks like the N/As weigh the same regardless of transmission unless they are auto and turbo, then they weigh more. The info in blue below is for the car this ECU is from.

04/96 YV1LS5727T3336284 1996 850, Sedan, Turbo, automatic, GVWR 4250, GA W R Front 2290, GA WR Rear 1980 LB
12/95 YV1LS5540T1310271 1996 850, Sedan, N/A, 5sp, GVWR 4180, GA W R Front 2240, GA WR Rear 1980 LB
01/96 YV1LS5549T2311218 1996 850, Sedan, N/A, automatic, GVWR 4180, GA W R Front 2240, GA WR Rear 1980 LB
03/96 YV1LS5541T2324237 1996 850, Sedan, N/A, 5sp, GVWR 4180, GA W R Front 2240, GA WR Rear 1980 LB