4-Pin Variable TPS on MT Setup
So fellaz.. I am living proof that life indeed does happen and we forget to come back here to share the ideas and findings we get on topics such as this..
We get too busy or lazy and just give up on being consistent here..
Speeches aside, I have a small update. I managed to iron out more of the quagmire and here's how. Please note this is applicable to the EMU configuration which I'm running at the moment. I'm sure it can be copied across similar setups.
First off, you will need some things;
- Diodes, x2 pieces
- NO automotive relay
- Soldering gun, solder, shrink-wrap etc
- Multimeter
- Loads of patience
What I did was;
- Identify the VCC feed to the MAPS and splice into it. Use enough wire to neatly reach the TPS area and tape everything off securely. You could also tap it from the ECU side. Whichever is easier for you
- Extend the TPS wires (not necessary but recommended).
- Solder the diodes on the VCC and IDL wires with the gate facing the TPS, meaning current will only be allowed to flow to the TPS. This is to prevent unwanted voltage feedback as the TPS operates.
- Connect the VCC feed to Pin #1, E2 to Pin #4 and IDL to Pin #3 (Pins on the TPS).
- Ignore the VTA/PSW feed on the harness.. or, as in my case, I used the existing wiring to feed the EMU TPS feedback wire instead of running fresh cabling.
- On the ECU side, I then used a fresh connector pin to connect Pin#10 (PSW) on the 16-pin plug to the relay. It needs to be a NO (Normally Open) relay in order to only bridge the link once the EMU is configured to do so.
- You can use either the VTEC/NVCS configs on the EMU to the trigger the relay when throttle input is at 65/70% and this will then trip the PSW feed at the relay to ground, which will then give the ECU the correct pedal information. This is the phase I'm currently at and haven't tried it hands-on but the theory makes sense and I'm sure it will work.
Short of drawing up a diagram, here's the look of things after it's all said and done.
Harness Side ---------------- TPS Side
VCC --------- >| ----- (diode) Pin#1
E2/GND ----------------------- Pin#4
IDL ---------- >| ----- (diode) Pin#3
EMU --------------------------- Pin#2 (to give variable throttle feedback)
Planning on a rolling road session so everything needs to be tip-top as I especially want to set up an acceleration map..