Maroc - SAU.COM.AU - content - 17/May 12:35

Gentleman’s Skyline

Engine ManagementECU: R34 GTT Manual ECU - P/N: 23710-AA500 - The C35 Laurel's only came in automatic, with the RE4R01A (basic T-bar shifter) or the optional RE4R01B (tiptronic). These shared the same set-up as an R34 whereas the RB25DE (NA) models had the transmission controlled via a separate module, aptly named the Transmission Control Module (TCM). The RB20DE & RB25DET models have the TCM contained within the Engine Control Module (ECM/ECU) as per page AT-3 of the Service Manual. The decision to go the manual ECU route was due to a robust discussion on here in relation to the TCM, whereas it was believed the GTT Auto ECU could conflict with the TCM. Long story short (and would love to hear how @Kinkstaah went as he had a fair bit of involvement with this in the OG days), I went the R34 GTT Manual ECU and it worked flawlessly (inc. use of tiptronic) except for the side-effect of losing the gear indicator on the instrument cluster (as also experienced by @albyz34gt ). I will tinker with this one day and update if I ever find a solution (or probably go manual...). NISTUNE*: There are numerous different approaches to tuning the turbo conversion, and can confirm the car will start and run on the R34 GTT ECU without issue (as reported elsewhere), however my intention was to have car tuned for longevity with the hope of making it somewhat reliable. I liked that NISTUNE was an Australian-based platform with plenty of support even in this day and age. I ordered directly via NISTUNE, sent my ECU via Australia Post, and received it back shortly after installed. Obviously, you'll need to find a tuner to get the actual tune done... Error Codes/Check Engine Light (CEL) re Secret Squirrel Tweak: I was well prepared for the CEL due to the results of those before me, mainly due to the lack of the Traction Control System (TCS) the R34 ECU expects to see. As a result, the DE loom is missing 3 x signal wires which the ECU wants to receive a certain voltage from (Pin 47 = 2.6v, Pin 51 = 3.4v & Pin 53 = 4.7v). By using the 5V feed from Pin 48, you can add your own wiring to reach these voltages using diodes. If you have any CEL's before the conversion, I suggest to buy the PLMS or ECU Talk cable and diagnose this first (see next) otherwise you'll be chasing your tail. The most helpful thread for tackling this was found reading through THIS but also referenced THIS. The original thread re Secret Squirrel Tweak seemed to have been deleted, so I could never find a wiring diagram but after successfully clearing the CEL using two different methods (mainly out of curiousity), hopefully my diagram will be of assistance. I will cover the actual install method in subsequent posts. PLMS Cable (Consult Cable)*: The C35 (and R34) both utilise the Consult system to connect to the ECU. There are two reputable suppliers of this cable - PLMS or ECU-Talk, both Australian-based. Both are interchangeable i.e. PLMS works with ECU-Talk software. I bought mine via NISTUNE. At this stage, have found ECU-Talk's free Consult Software to be super easy to use for reading error codes with the PLMS cable via an old-school Windows laptop.