I'm putting a 2GB engine harmess into a 2GA Talon TSi. I know the differences lay within the cam sensors being different. What all would I need to change to use the 2GB harness with the 2GA ecu?

ABS wiring can be different. Location I think was changed in 99, maybe 98, from passenger footwell to front driver's corner.

This Talon has the abs ecu in the footwell, but the hydraulic portion in the front corner. Were you saying the ecu changed locations?
Anyone know if the wiring has to be inverted for spark and fuel?

The ABS ECU moved from the footwell to being on the pump itself in the front driver's corner.

Forgot about ignition. I do think the coil wiring needs to be swapped but that's easily done on the harness to the coilpack by moving the pins around.

Oh another thing, your CAS wiring will be different. 2GA had it via a sensor under the intake cam gear, but 2gb had it off the passenger side of the cam with a different sensor. I never had to deal with that difference personally so can't walk you through that, but I'm sure it' s documented somewhere. Might just be splicing a the matching harness or might be a bit more involved.

Yeah, I'v dealt with the cam sensor issue during 6 bolt swaps, but never with just a harness swap. I figured it'd be similar, just not positive. Might just be easier to get a 97+ ecu and cam sensor and avoid the wiring

"The wiring" is really only a matter of swapping plug wires and it all comes down to which ECU and CAS combination is being used. The wiring/harness does not change the signal the sensor is outputting, nor how the ECU receives it unless it is wired incorrectly from the start. In short:


That is all that this picture is saying. When the original order in any normal case is 4-1-3-2, then if a change is required, it will become:

The CAS connection is different between the two sensors as mentioned, so if using an early CAS with the late harness or vice versa, an adapter or new plug will be required to mate with the sensor. If using a '95-'96 harness and a '97-'99 sensor, the wires will need to be extended to reach the sensor. If using a '95-'96 sensor and a '97-'99 harness, the wiring will be plenty long but will need the correct connector.

Correct me if im mistaken, but only awd cars had abs correct?

ABS was available for all 2G models. It appeared in every trim model at some point or another.

Ive had 6 different 2g's in various trim levels and ive personally never seen one with abs (Though I do live in the far south)

Consider yourself lucky. I love the fact my Tsi doesn't have abs. Once I put the awd calipers on I'll have some fun.
Basically you have to match the ecu to the cas thats it. Only 95-96 had the inverted CAS. If you have link you can invert the signal or just swap in the proper ecu. When the cas on my 96 took a shit I stuck a 1g cas (same placement as a 2gb) and a 97 ecu in and good to go. Much easier than pin swap assuming you have a spare ecu as most dsmers should.

The 96 gsx donor I used for my previous spyder had abs, and this 96 awd talon has abs. The other 6 DSMs I've owned didn't, and they were various models.

I do have a spare 2ga ecu, so if I got this right, if I use the 2ga ecu and sensors, with a 2gb harness, all I need to do is swap around the coil pins or swap the firing order correct? What about injector signal?

Also so you all know why I'm asking, the harness from the talon is hacked up, and I have a spare complete 2gb harness in great condition. Would rather use the better harness even if I have to modify it since I know I'll modify it properly.

It depends what ecu you plan to use

spyderdrifter said:

The 96 gsx donor I used for my previous spyder had abs, and this 96 awd talon has abs. The other 6 DSMs I've owned didn't, and they were various models.

I do have a spare 2ga ecu, so if I got this right, if I use the 2ga ecu and sensors, with a 2gb harness, all I need to do is swap around the coil pins or swap the firing order correct? What about injector signal?

Also so you all know why I'm asking, the harness from the talon is hacked up, and I have a spare complete 2gb harness in great condition. Would rather use the better harness even if I have to modify it since I know I'll modify it properly.

Click to expand...

Don't get hung up on the harness, the only difference is the CAS plug. If you're running a 2ga CAS (behind the cam gear) use a 2ga ECU. If you're running a 1g or 2gb CAS (on the pass side of the valve cover) use a 2gb ECU. That's it. Don't mess with pins or anything else.
When using a 1g or 2gb CAS on a 2ga you'll need an adaptor harness or extension harness respectively.

PlanZero said:

Don't get hung up on the harness, the only difference is the CAS plug.

Click to expand...

You should really read this:

http://www.dsmtuners.com/threads/95-96-vs-97-99-harness-differences.455871/

I did read through that, good info.

...and because of it, I'm just going to make repairs to the hacked up 2ga harness instead of modifying the 2gb harness. As some have mentioned, it seems to only matter what ecu and cas combo I'm using, which I thought I stated in my original post, but perhaps it wasn't clear. The car is 2ga, so all the sensors and ecu are remaining that way, and the only change I was going to make was the engine harness. Now I'm not going to do that, and just fix the bad one so everything matches and nothing needs pin swaps or plug changes.

It should be noted that in 1999 the engine harness and interior harness varied slightly from 96-98.

The main two differences im aware of are moving a few emissions items around the engine bay and the main ecu ground behind the radio.

Yeah same goes if you put a black box ecu in a non black box car. New CELs

I was specifically talking about CAS/firing order differences between harnesses. This seems to get overcomplicated because of the pin swap method. Personally I've found it much easier to just match cas/ecus in a car without link. Of course you'll encounter other harness differences but they're extremely easy to adapt to if you have the old harness to make adaptors

PlanZero said:

Yeah same goes if you put a black box ecu in a non black box car. New CELs

Click to expand...

I have a black box ECU in my 1995. I have a 2GA CAS and have moved injector pins around at the ECU. I forget if I did anything with the spark plug wiring itself or if I re-pinned the ignition also.

I saved the stock rom from that ECU before installing Ceddy Mods. On the stock rom, I do not throw any CELs. My tank vapor setup is fully installed. I've eliminated the EGR valve and have only thrown the MDP sensor code one time in several thousands of miles.

I installed the black box of course to gain Ceddy mods. Within a few minutes of driving with the Ceddy rom installed, I will throw random emissions related CELs. All I was looking for on that car was to gain control of the fan turn-on temps but the side effect was throwing so many different CEL codes that I nearly bricked my ECU due to the number of periphery bits I was toggling. Luckily, I'd saved the stock rom image (not Ceddys) and was able to rescue the ECU and get back home. I haven't even considered loading Ceddy Mods back up due to the stock nature of the car and CEL issues.

What I'm getting at with all of this is that the CEL issue isn't something necessarily tied to a H8 ECU in a 2GA w/ 2GA equipment- that is honestly a perfect setup with zero issues. The problem is in the Ceddy Mods roms when using the H8 ECU in a 2GA- that's when I start throwing all sorts of CELs.

I'm not saying you definitely will it's just a general consensus that you probably will. There is no reasoning. Most times you'll get emissions codes when using a black box in a pre 98. I did (96 and 97). But some people don't. Sometimes you'll still get emissions codes with the solenoids plugged in on a 2g. Happens on 2 of my 2gs. Personally IDC about CELs but some people do.
Now that you mention it I remember on a 95 GST I used to have it did not throw CELs with the solenoids plugged in. Perhaps because it was an obd transition year?
Ntm the ecu reset key off problem that plague 2gs. It's not consistent, but enough that 96 talons (not eclipses) are exempt from emissions testing because of a continual not ready status of IM monitors. But I digress..