[WrxSwap]

We're putting a 2009 JDM 2.0l turbo w/6 speed manual in a 2002 WRX formerly automatic. We did an engine swap last winter on the same car with an older JDM engine and that all went fine. Good engine, but it's time for more horsepower and a 6-speed manual. Mechanically it's complete. All the mounting is done, drivelines are in, etc.
Electrically still having some issues. We've had to build the wiring harness to match the 2009 engine. With the help of another member of this forum who provided drawings in Japanese of the dual AVCS and cam sensor connections, we recently completed those circuits.
To begin with, the ECM is not closing the main relay. The attached file shows the 2002 and 2009 main relay pages and the difference in how the two systems work. In 2002 one side of the relay coil is grounded with the ECM providing voltage to close the contacts when the ignition is turned on. In 2009 its the opposite. The relay is powered up by the main fuse box and the ECM grounds the other side when you turn the key on. In our case, this is not happening. In fact, none of the relay circuits are working (I added these in using parts from a 2009 wiring harness) - to include the throttle control and starter relay.
If I close these with jumper wires we get the fuel pump to cycle (pressure at the rail), the engine cranks, it throws some trouble codes via the OBDII connection, but no spark or injector pulse.
I have not wired up the secondary air pump and its relays - I'm assuming that won't stop the ECM from sending fuel and spark - could be wrong. This does cause some trouble codes. I also know these cars will start without an electronic pedal position sensor connected. We confirmed this with our 2009 Forester. Here are all the codes:
P2103 Throttle actuator control motor circuit high
P2127 Throttle/Pedal position sensor/switching E circuit low input
P2122 Throttle/Pedal position sensor/switching D circuit low input
P0413 Secondary air injection switching valve A circuit open
P0418 Secondary air injection system relay A control circuit

A few other troubling possibilities: I believe the 2009 is CANBUS while the 2002 is not. I don't know if this is a show stopper or if it just means some of the dash functions won't operate. Our fuel level gage works and the check engine light comes on.
And, the ECM we got with the engine may be immobilized. The two wires for the immobilizer function to the ECM are not in the harness (B136, pins 26 and 34). I've heard different things - all of them starting in 2005 were immobilized or it was a factory option - not sure which is true. We've also heard different theories on how the immobilizers work - some say it completely stops spark/fuel, others say they'll start but then shut right down. Seems like the main relay should come on though regardless.

We're starting to consider a stand alone after market ECM or a non CANBUS USDM ECM with key set, etc. (these only operate the intake AVCS), the engine has the exhaust too.

If anyone can shed some light, it will be appreciated!

 

[1 Lucky Texan]

The 2002 was 'traditional' throttle, with a position sensor for ECU feedback. the 2009 is drive-by-wire so, you probably need a DBW pedal assembly? Seems like the ECU is expecting pedal assembly signal. Or, some kind of throttle body mod? Dunno if the new engine can take the old intake but, that could be a solution, may need the other ECU though.......

Is that secondary air the same as 'air cut' ? If so, the valves may be stuck or there's a wiring issue etc. On my 06, I had to kill 14 codes related to the air cut system. Luckily, my valves were stuck closed. many people remove the entire system , flash-out the DT codes and install block-off plates.

There are others here that have WAY more experience than me. But, you could also post the question at ultmatesubaru.org . User generaldisorder has built many customized subarus and may have some insight.

 

[WrxSwap]

The 2002 was 'traditional' throttle, with a position sensor for ECU feedback. the 2009 is drive-by-wire so, you probably need a DBW pedal assembly? Seems like the ECU is expecting pedal assembly signal. Or, some kind of throttle body mod? Dunno if the new engine can take the old intake but, that could be a solution, may need the other ECU though.......

Is that secondary air the same as 'air cut' ? If so, the valves may be stuck or there's a wiring issue etc. On my 06, I had to kill 14 codes related to the air cut system. Luckily, my valves were stuck closed. many people remove the entire system , flash-out the DT codes and install block-off plates.

There are others here that have WAY more experience than me. But, you could also post the question at ultmatesubaru.org . User generaldisorder has built many customized subarus and may have some insight.

Thanks for the response! We do have the DBW pedal assembly wired in. At one point we were getting some buzzing and apparent movement from the throttle body but that hasn't been consistent. I also just discovered the ECM is not sending 12v out to the AVCS oil flow control valves. The thing could be toast. Putting the old intake on the new engine is a definite possibility. We have all the parts and the old ECM which worked fine.

The secondary air is a smog device. It pumps extra air into the exhaust system at certain times to help rid unburned fuel prior to the catalyst. If we go the old intake route, its gone!!

I will give ultimatesubaru.org a try. Appreciate the comments!!

 

[1 Lucky Texan]

Thanks for the response! We do have the DBW pedal assembly wired in. At one point we were getting some buzzing and apparent movement from the throttle body but that hasn't been consistent. I also just discovered the ECM is not sending 12v out to the AVCS oil flow control valves. The thing could be toast. Putting the old intake on the new engine is a definite possibility. We have all the parts and the old ECM which worked fine.

The secondary air is a smog device. It pumps extra air into the exhaust system at certain times to help rid unburned fuel prior to the catalyst. If we go the old intake route, its gone!!

I will give ultimatesubaru.org a try. Appreciate the comments!!

yeah, that air cut system seems similar to my car. It was only active on a cold start and then only for a minute or ???? Just to get the cat conv to 'light off' quickly.In humid climates, those valve are notorious for sticking . There's a huge thread at NASIOC about them. I have a post or 2 there from way back when my valves failed.

we also have a user here , @west_minist , that may be able to help you - maybe with a tune after you get some of these install problems solved.