Nissan 180sx ECCS - NS15X retains power after key off

[jdniss]

Hi,

ECCS related issue I'm struggling to find an answer for - I suspect due to varied Nissan OEM ECU's and wiring across the S13 SR20 / 180sx SR20 production years.

I have a 64pin Plugin NS15X in a Nissan 180sx ('94 chassis) with an SR20DET ('96 model "Type X" engine),
Car starts and runs - however on key off, the ECCS relay doesn't seem to be de-energized and the ECU retains power.
If I pull the ECCS/IGN relay first - the ECU gets power once the key is turned to IGN - and shuts off when the key is removed, as per normal.
 

The original Nissan 'J4' ECU - and the PowerFC that Link is replacing - don't have this issue;
I'm assuming there's something internally within the Link that is wired differently to the factory-style ECU's that don't exhibit the same behavior.

Either that or there's wiring commonality across at least S14~S15 that may differ to older S13's?

Thanks

[KennyJ]

probably a back feeding issue

measure at the connector which aux keeps getting back fed , some R chassis its the aircon clutch for example

switching pins around to unused injector outputs solves this 

[Adamw]

Yeah, typically this will be a backfeed from something connected to an Aux output with a permanent 12V feed rather than an ign switched supply.  Most likely this will be something non-factory that has been added like a boost solenoid, fuel pump or fan relay etc.  I dont remember any factory non-compatible wiring in any models this ecu fits.  

[jdniss]

Hi,

Bit of an update here;
I've flipped the jumper settings from all horizontal to all vertical as per the manual - and the "retains 12V with key off issue", has gone away.

However I've now noticed I only have coils #1 & #2 - test fails on coils #3 & #4;
This was tested with factory coils including OEM igniter - though I noticed coil #4 was getting hot.

Also tested separately with aftermarket coils (Toyota Yaris Denso coils) including an igniter bypass - no change - test fails on coils #3 & #4.
Validated the offending coils are OK on a known working output ~ coil #1.
The "retains 12V with key off issue" comes back if I leave coils #3 and #4 disconnected.
The Yaris coils work with the outgoing PowerFC, so I don't believe that sub loom or coils are bad.

I flipped Jumpers J1 + J2 horizontal and switched pins 2 & 3 as cited in "Known Issues" - still no change on coils 3 & 4.

 

The G4+ / G4X NS15 pin-outs match the 180sx J4 ECU pin-outs I have, so I'm a little stumped.
Pin #1 - Coil 1
Pin #3 - Coil 2
Pin #5 - Coil 3
Pin #25 - Coil 4

 

Thanks

[Adamw]

Your jumpers should be in the 94-02 position (all horizontal).  Since your ecu powers down with the jumpers in the incorrect position that may suggest your back feed is coming from the AC fan relay.  Can you try it with J5 & J7 (marked below) unplugged, with all the others left connected horizontally per 94-02.  If it then powers down with those jumpers removed then your backfeed is coming from the AC fan relay on Pin 9 or 10. 

 

[jdniss]

Hi,

Issue is fixed now - changed jumpers back to all horizontal - whatever the backfeed issue was - is gone;
All 4x coils test and fire as expected, same with all 4x injectors.

Car starts and runs as per normal.

Not entirely sure what the issue was as I can no longer replicate it in any prior configuration.

 

Anyway, all fixed.
Thanks for the help @Adamw, @KennyJ

 

180 g4x running.pclx 180 g4 plus running.pclr

Edited September 4 by jdniss
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