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[VT-VX] Relocating LS1 PCM

Discussion in 'Holden Commodore How-To's' started by Irukanji, Apr 22, 2017.

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  1. Irukanji

    Irukanji 101% Lunacy

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    I tried finding a write-up on the interwebs which led me to another Commodores forum and wanted me to sign up, it won't accept a Gmail so **** em, JC can get a fresh write up.

    In the quest for more power, a turbo is going to be used. To make room for a dump pipe, the computer needs to go. The radiator will also be replaced with one from an R33-34 skyline to simplify the tubing arrangement in these models(both inlet/outlets are on the same side, a VZ radiator could be used but it still has the shitty piping arrangement and I can't mount it further forward to give the fans some wiggle space from the crossover)

    So, lets begin.

    Tools;

    13mm spanner(for the battery)
    10mm and 7mm socket(for the computer plugs and the plastic holder
    Plastic trim levers($5 from repco)
    Small jewellers flat head screwdriver
    T25 bit for the radiator tank(or just pull it off, like everyone else)
    2 bits of wire(brown and green work)
    Soldering iron and solder
    Heatshrink(3mm?)
    Lighter
    Electrical Tape
    Torch

    Method;

    1. Disconnect your battery. Double check it's disonnected.

    2. See above.

    3. Begin by removing the radiator tank. Make sure it's cool. It might be easier to just yank it off if it's still warm, though. Unplug the sensor wire on the bottom first, though.

    4. Remove the heatshield off the side of the PCM(black box under the tank, if you aren't familiar). Grab it and pull it up, and it should come free. It's just wood with foil but it's a tight fit. (to the right of the pic)
    [​IMG]

    5. Open the top of the black box and you'll see 2 big connectors. Use your 7mm socket and undo them. Once fully undone, try to lift the wire end up. Be gentle, you don't want to rewire these bastards.

    6. Place the PCM on your passengers seat or somewhere safe.

    7. Begin carefully peeling back the tape near where the coolant temp sensor joins until the grey plastic is free'd. Cut along the grey to expose some wire, enough to strip.(more if you use pliers like me, less if you have a tool). Join the respective ends together with some of the wire. Remember, heatshrink goes on first, and far enough away to not shrink when you solder the joint. Once connected, wrap it in tape and maybe get some of the corrugated conduit if you have it.

    8. Crawl inside the car, and become a contortionist. Reach up behind the glovebox and locate the big ass plastic connector. It's held in with a few clips, just push 2 in next to each other and push inwards, and it should slip down enough to make your life easier.(image is looking up, from the floor.)
    [​IMG]

    9. Remove the kick panel. You may need to remove the plastic trim which clips in just behind the glovebox first.(Mine long since disappeared, but from memory you just pull down near the tunnel, and it pulls out of the side. Next, remove the plastic oval shaped bit on the side trim and undo the 4 torx bits underneath. Then 2 phillips head screws and it'll come free. Unplug the BIM.

    10. Whilst you're in there, pull the BIM out, there is a clip underneath which you can easily push with a screwdriver, and it'll lift out without issue.
    [​IMG]

    11. Jump put of the car and stretch, it helps. Grab a drink, do what you gotta do. Now go to the shed and cut the BIM from the plastic surrounding it. It's only Nylon and Glass fibre(PA6 33% GF according to the cast marks), so it may help to have a sharper, fine tooth jigsaw blade to make your life easy. Hacksaw would also work. Step dad had a Ryobi "Multitool" and it ripped through it, 10/10 would recommend.

    12. Go back to the car and pull the plug off inside the engine bay. You'll need to undo the tape holding the BIM wiring into the rubber, then cut the rubber free. Luckily you undid the plug, so you can work on it at a sensible height. Unclip the plastic bit by pushing a screwdriver into one side and twisting it free. You may need 2, but 1 works once you see wtf is going on.
    [​IMG]
    [​IMG]

    13. Now the fun begins. Cut a line through the corrugated tubing surrounding the main loom running to the plugs approximately where it will run through the firewall. You only need to seperate the 2 halves. As you'll see, the plastic plug doesn't fit over the corrugated plastic. Push the loom into the bottom half with the BIM wiring on the cabin side and the temp sense wire running out to the engine bay. Push the other side on top. It'll help to put the 2 smaller cables on the bottom and push the huge one on top. Dodgy install, waiting on some 5mm corrugated to make it look neater(the green and brown wires, taped together but look kinda dodgy in the bay, over the strut tower)
    [​IMG]

    14. Run the BIM and 2 connectors through the firewall. They fit, one at a time. Push the plastic thing back where you found it. I tried cutting the rubber dust boot to accomodate but by the time it was big enough to fit it all through, it wasn't going to do ****. Luckily it's a tight fit through the plastic plug, so shouldn't let much **** in, if any. Give it a shot of sikaflex/silicone if you're worried/expect to go underwater.
    [​IMG]

    15. Find somewhere nice to put it. My huge fire hazard of an audio install was in the way, so I had to rearrange/tidy it up a fair bit. With the trim piece off, in the corner, you'll see where the carpet doesn't quite reach the wall. Pull it up and see if the computer will fit. If it does, connect it with the socket(on the top of my computer it says something "blue", it's where the blue connector goes if you're wondering). Factory says something like 3Nm, basically push down on the connector until it bottoms out, tighten until starts compressing the connector and then give it a small nip. Shove it back into the corner spot. Plug in the BIM and velcro it in place. I found it would sit on top of the PCM, and be held in with the trim. Place the trim back on. It's a proverbial snake pit. Luckily it's cleaned up now, no more dodgy MDF holding the amplifier on the floor which I'll "one day" sort.
    [​IMG]

    16. Plug the temp sensor(or is it a level sensor?) into the bottom of the tank and reinstall the tank. Marvel at the amount of free space you have acquired.
    [​IMG]
    17. Reconnect the battery. Start her up. For some reason it takes 3 on/offs before it'll idle right with the MACE mail order, something to be aware of.

    It's all relatively straight forward, you're just pushing 2 plugs through the firewall and lengthening 2 wires.

    Finished shot, showing poverty spec floor mats(to be replaced), showing it looking normal after the chaos. It's tucked in on the left, amplifier now hanging under the glovebox.
    [​IMG]
    Soz for the h00ge pics, even 25% resize has em too big.


     
    Last edited: Apr 22, 2017
    Craig Facey likes this.
  2. Nickspa113

    Nickspa113 New Member

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    I am doing this relocation on a vy calais ls1. What is the bim? Is it ignition control module?Tia
     
  3. EYY

    EYY Well-Known Member

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    What do you actually want to know? I’ve done it.
     
  4. James Royston

    James Royston New Member

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    Thanks for your posting, it was really helpful. Cheers James
     

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