Truck Side wiring

[greenvortec]

So here is what I've found. These are the pins on the LS ECU (99-02) that need to be connected to the truck:

C1 BLUE
19 PCM IGN Supply (12+ switched)
20 PCM Battery Supply (12+ constant)
33 TCC Brake switch
42 Fan 1 Relay Ground
57 PCM Battery Supply (12+ constant)
58 Serial Data to OBD2 Port
71 Tow/Haul Mode switch (Momentary Ground)
75 PCM IGN Supply (12+ switched)

C2 RED
9 Fuel Pump Relay Control
10 Tach output signal [connects to white wire behind cluster?]
16 4WD Low signal (only used if VSS on Tcase Output)
33 Fan 2 Relay ground
38 Fuel gauge output (runs level gauge on 96-99 trucks)
46 CEL signal wire
50 VSS output [connect to light blue wire with black stripe and red wire with white stripe in DRAC box?]

So... I beleive the ones in bold are the only ones I'm not fairly confident of what to do with. I'm fairly confident that the rest will be fairly easy to figure out.


NOTE: This pinout ignores EVAP, rear O2s, AC, and probably a few others some people may care about but I tried to make this not just dedicated to my swap, as I've found the info out there for where to actually hook this stuff up seriously lacking (compared to all of the other topics).

Also, I see nothing in the factory harness info I found for oil pressure... this surprised me. Wouldn't it be wise of a MFR to have a low oil pressure safety built into the ECU?

the PCM does not care for oil pressure, you can use the stock plug on the actual truck harness and use it on the Oil pressure sensor, as for the TCC lockup brake switch deal, im still trying to figure that one out.
It would help you alot if you found a pinout for your year model truck

[greenvortec]

the PCM does not care for oil pressure, you can use the stock plug on the actual truck harness and use it on the Oil pressure sensor, as for the TCC lockup brake switch deal, im still trying to figure that one out.
It would help you alot if you found a pinout for your year model truck

Hey man, Redheartbeat told me what to do and it works. go under your dash and find the brake switch, there should be a purple wire that comes out of it along with a few others, i tested mine with a volt meter first, it needs 12v with the pedal untouched and 0v with it pressed down!

[Wagonbacker9]

5th post updated with what I believe to be complete info based on forum research.

[Dustytrix]

For the tach on a 92 silverado I connected to the white wire that was on the coil, using the red wire that was on the coil for ignition switched power. But even using the white tach wire that was on the coil you need a 680 ohm resistor. It will read only half rpms that you are running, I don't know how to get that straight but its better than nothing. you are right also with the existing fuel pump relay tie into the green/wht wire. Hope this helps.

[Wagonbacker9]

For the tach on a 92 silverado I connected to the white wire that was on the coil, using the red wire that was on the coil for ignition switched power. But even using the white tach wire that was on the coil you need a 680 ohm resistor. It will read only half rpms that you are running, I don't know how to get that straight but its better than nothing. you are right also with the existing fuel pump relay tie into the green/wht wire. Hope this helps.

Appreciate the input.

[Dustytrix]

For the speedometer I ended up splicing the vss wires from 04 computer into the vss wires on the transmission this makes a 3 wire splice for both colors (6 wires total) that made my speedo start working

[Wagonbacker9]

For the speedometer I ended up splicing the vss wires from 04 computer into the vss wires on the transmission this makes a 3 wire splice for both colors (6 wires total) that made my speedo start working

This is lacking a lot of info.... details?

[gagliano7]

http://www.ls1truck.com/forums/lsx-t...eedometer.html Also do a search in this forum "speedometer" and you will find a lot of info and pictures.