82transam

iTrader: (18)

This might seem like a stupid question, but I have to ask anyway. I have swapped a JDM S5 13BT into my first gen, using the N374 ECU and matching JDM harness.
I used a US dash harness to power the coils, main relay etc, and everything seems to working alright, but there is no check engine light. It doesn't come on when I turn the key, and unless I'm doing something wrong to check codes, its not working then either.
I know the JDM ECU has some different pinouts on the engine side of things, but is the check engine light powered by a different pin than the US cars?
Also, the light I wire in should have one side going to teh ECU and the other side to a 12v ign source right? The ECU grounds the light?
The car has some idleing issues, and its proving to be hard to diagnose without being able to read codes. Any help would be appreciated
Thanks
Sean

Suave1

iTrader: (2)

try the bulb.

b18crx

iTrader: (3)

i would also like to know about this cause i have a n374 ecu and my car wont show the check engine light but if i throw in the us n350 ecu i have then it shows the check engine light so im not sure if its a system in the ecu failing in the n374 or if they simply dont use check engine lights. somebody please inform us. -mike

82transam

iTrader: (18)

I used a few different bulbs, one of them being my test light, so thats not the problem. I'd find it hard to believe that the JDM ECU has no check engine light. I'm hoping someone can comment on the pinouts, to confirm that it sthe same wire as on a US computer....

NZConvertible

Japanese FC's don't have a check engine light. Codes can be read in exactly the same manner as S4's, by connected an LED to the green 6-pin diagnostic plug. The diagnostic plug is in the FC's Front harness, so you should have it. Basically you connect one LED up to the diagnostic plug in the same way as it done for the S4 (positive to the black/white wire or any 12V power supply, negative to the yellow wire), trigger the code display as per the S5 instructions, and read the codes using the S5 info.

82transam

iTrader: (18)

Ok I was worried that I had wired something wrong, I took a lot of time laying everything out, at least I know it wasn't something I did. I do have that 6-pin connector so I'll have to play around with that this weekend. Thanks!

82transam

iTrader: (18)

I know this thread is incredibly old, but I need to resurrect it. To be honest I never was able to get any codes out of this thing, but was able to get it running really well about a year and a half ago, and have been driving it ever since (other than winter) but this weekend it started running really crappy and I can't seem to figure out why, being able to read codes would be helpful,
I made a test light to set the TPS out of some LED's and it looks like the same one could be used to check codes. If I plug it into the 6 pin green plug near the driver side strut tower both lights go on and stay on, once I ground the single pin green plug both go out and a second later the one on the yellow wire illuminates and then stays on. What am I doing wrong? Also, the FC3s pro site notes that there should be 4 wires going to that 6 pin connector, however S5's only have 3 wires, this is still the way to check codes right?
I'm unable to drive the car without it bucking, backfiring and struggling to move, so any help is appreciated.

Rub20B

My S5 also has no check light, it's an US body with european turbo2 engine and I tried with both N374 and N380 ecu, if you look in the manual it says that you should be able to measure pin 1F and 1D IIRC being pulled to ground for 3 secs after you switch the egnition on, but this does not seem to happen here, not even with the green one pin test connector grounded..

I have some issues with running way to lean (afr21) under light load under vacuum (= normal closed loop operation), and then with the slightest bit of more throttle it goes away and it regulates nicely at 14.7-15, for the rest the car drives very good, it's worse with the lights on.. I tested tps, and it's fine, fuel pressure is fine, ground points all look fine, it happens with both ecu's

Rub20B

little update,

I connected the led as said to one of the yellow wires at the check engine light connector, first it seemed that it didn't work, because the led staid out after iluminating for 3secs after ign on.. now this seemed to be because there were no error codes, I induced one by unplugging the AFM, then it gave the 2 error codes, 8 and 10 =)

I'll take it for a test spin now and see if it throw up more codes after I let it stumble a while under light load due the lean condition