Hrv- sierra 95 rcsb

[Chevy-Art]

If the speedometer is not working, the trans will not shift into 3rd and 4th gears. Use this link it may help you.
http://www.ls1truck.com/forums/lsx-t...ol-wiring.html

[HRV-LS1]

I looked over that thread. My wires at the vss are green and yellow. I'll try changing them around again. One thing I forgot to mention was that my tach is working either. Bought a
module for it thats suppose to make it work. Got to look into that also. Could that tach have anything to do with my transmission not shifting too? Another question, if i plugged in the transmission connector (on the passenger side) in backwards, could that cause this problem?

[kewljay223]

what did you do with your pcm? i assume you got the vats removed. did you also have it set up to run the rest of the parts on your truck? im pretty sure the tach signal can be changed to 8 cylinder and you need to tell the pcm which trannyto controll. what was behind the motor in the suburban? im not sure why you were trying to drive it without the rectangular plug installed... and as for the tach, if you have an 03+ pcm, you just need to add the resistor which is what got mine working. http://lt1swap.com/lsx_tach.htm

you should check out my swap thread. lots of useful info in there that im sure will help you out. also there are some diagrams i posted on the tranny plugs.

[HRV-LS1]

what did you do with your pcm? i assume you got the vats removed. did you also have it set up to run the rest of the parts on your truck? im pretty sure the tach signal can be changed to 8 cylinder and you need to tell the pcm which trannyto controll. what was behind the motor in the suburban? im not sure why you were trying to drive it without the rectangular plug installed... and as for the tach, if you have an 03+ pcm, you just need to add the resistor which is what got mine working. http://lt1swap.com/lsx_tach.htm

you should check out my swap thread. lots of useful info in there that im sure will help you out. also there are some diagrams i posted on the tranny plugs.

The pcm was handled by S & P. They removed the vats, put in tire size and rear gear ratio. The pcm is suppose to run the engine and trans, for all I know. I believe the suburban had a 4l60e behind it, but I didn't actually see it. That rectangular plug on the drivers side has been plugged in. I have a new rectangular plug from the new harness that I'm not using.

[kewljay223]

well if they set it up for your swap then you should be good to go. i had the same done to mine and it shifts into all grears like its supposed to....hhmmmm. but why arent you using the new plug since your new computer is whats controlling it...??? i think thats your problem... im assuming the new one is just dangling down there? try pluggin it in instead. i bet that fixes it. i cut out my old one and let the new pcm cotroll everything and it seems to work flawlessly. worth a shot

[HRV-LS1]

well if they set it up for your swap then you should be good to go. i had the same done to mine and it shifts into all grears like its supposed to....hhmmmm. but why arent you using the new plug since your new computer is whats controlling it...??? i think thats your problem... im assuming the new one is just dangling down there? try pluggin it in instead. i bet that fixes it. i cut out my old one and let the new pcm cotroll everything and it seems to work flawlessly. worth a shot

Who did your harness? S & P did mine. At the start all the new plugs were plugged in. But the truck wouldn't start, no power to selector switch. Plugged back 2 old plugs at selector switch, and truck started and power to selector switch. Now it won't shift to 3rd, 4th. I'm thinking they didn't program it right. Now there telling me to put a scanner to it, I don't want to shell $400 for a scanner. I didn't read your entire thread, is yours smog legal? I bought a module for the tach, need to reprogram it, shouldn't be a big problem.

[kewljay223]

i did the wiring myself. my motor came with the harness/pcm/fuse box so i just married the new harness to the truck. i also kept the old fuse box cuz i didnt want to change anything existing on the rest of the truck so i now have two. as it sits now, the new pcm controls everything powertrain wise. the old pcm is in place pretty much just for the abs. but it sounds like your controlling the motor with the new pcm and the tranny with the old pcm since you have the old plugs pluged in.. i dont think that can work.... im pretty sure you need to use the new pcm.

idk what they did to the harness so it will be difficult for me to diagnose. you might just have to start tracing wires out.... what kind of scanner are you referring to? that seems steep. is it just to see what codes the pcm is throwing? i bought this tool for my laptop and it works great. http://www.scantool.net/scan-tools/p...bdlink-sx.html

my truck is going to be smog legal. just got it running last week so i still have a little bit more to tidy up before i take it to the ref. hope i pass!!

[HRV-LS1]

The new pcm is suppose control the engine and trans. When I plugged everything in, it couldn't start and there was no indicator light at the selector switch. I thought I was suppse to plug in all of the new connections and thats it. S & P told me to try plugging in the old 2 connectors at the trans selector, I did and it started and the light came on. The 1 connector with the 6 wires at it ( for the trans selector) has a purple wire that goes to my starter. Thats why it started. So at the trans, the only new connectors plugged in are the round one on the passenger side, and the vss. Could it be that they didn't program the pcm correctly? Maybe the only old connector that needs to be plugged in is the 6 wire one at the trans selector (because of the wire that goes to the starter wire).

[kewljay223]

well it is def possible that they didnt program it right. dont see how they could make that mistake but hey, we all do it. i need a bit more info tho. did you get the harnes and pcm with the motor and send it to them to modify or did they make one from scratch? i find it odd that they would tell you to plug in the old connectors if the new harness they worked on has the same ones.... that sounds fishy to me. i understand what you mean by the starting problem. in my thread there is a section specifically on that connector so i understand the differences between the old and new. the new one starts the car very differently. but i can tell you from my experience that it should still start it if wired correctly. the only wire i had to modify on that connector is the light green which turns the reverse lights on. my prnd light does not work and thats my bad. i think i forgot to hook that one up. but other than that the new pcm starts the car. you shouldnt have to use the old plugs. thats why im concerned as to why they told you to do that... very odd. do u know how to read a wiring diagram? i can post each one and explain it for you but you will have to trace it. let me know if you want me to do that.

[HRV-LS1]

well it is def possible that they didnt program it right. dont see how they could make that mistake but hey, we all do it. i need a bit more info tho. did you get the harnes and pcm with the motor and send it to them to modify or did they make one from scratch? i find it odd that they would tell you to plug in the old connectors if the new harness they worked on has the same ones.... that sounds fishy to me. i understand what you mean by the starting problem. in my thread there is a section specifically on that connector so i understand the differences between the old and new. the new one starts the car very differently. but i can tell you from my experience that it should still start it if wired correctly. the only wire i had to modify on that connector is the light green which turns the reverse lights on. my prnd light does not work and thats my bad. i think i forgot to hook that one up. but other than that the new pcm starts the car. you shouldnt have to use the old plugs. thats why im concerned as to why they told you to do that... very odd. do u know how to read a wiring diagram? i can post each one and explain it for you but you will have to trace it. let me know if you want me to do that.

They made a brand new wiring harness for me. The engine came with a harness, pcm, etc. The new connector that goes to the trans selector, has 1 wire in the connector. The old one
has 6 wires. I think I'm suppose to somehow add the old wires to the new connector to make this work. I know there are 2 connectors that go to the trans selector. The second one, which has 4 wires going to it, doesn't work when plugged in. When I use the old one ( 4 wire connector), then the selector lights up. I believe I can read wiring diagrams, I use to work on refrigerated containers. Any help would be great.