Megasquirt install confusion

[GlazedDSM]

I am trying to figure out how to install the MS2 I recently purchased used but still in the box. I want it to replace the stock Ecu I have searched and searched I am not finding anything new just years old of information. I have MS2/extra version 2.0.1. I read the install on the MSnS but that is not how i want to install it. how does it work by itself without any transmission sensor hooking into it? I simply just can not grasp the concept of it. I also assume the map sensor is the vacuum that is on the ecu? I have an extra wire harness just for the MS to get the sensor pigtails

 

[VelocitàPaola]

I am trying to figure out how to install the MS2 I recently purchased used but still in the box. I want it to replace the stock Ecu I have searched and searched I am not finding anything new just years old of information. I have MS2/extra version 2.0.1. I read the install on the MSnS but that is not how i want to install it. how does it work by itself without any transmission sensor hooking into it? I simply just can not grasp the concept of it. I also assume the map sensor is the vacuum that is on the ecu? I have an extra wire harness just for the MS to get the sensor pigtails

Where did you get it from? Whoever built it should be able to answer most of your questions.

MegaSquirt EMS just controls the engine, so it doesn't need information from the transmission or VSS.

The vacuum port is indeed its internal MAP sensor.

 

[GlazedDSM]

its symtech labs i bought it from a user on here so i still have to keep my stock ecu and megasquirt ecu? thats my main question

 

[VelocitàPaola]

its symtech labs i bought it from a user on here so i still have to keep my stock ecu and megasquirt ecu? thats my main question

Nope, you can remove the stock PCM. The MegaSquirt ECU should have a tachometer output and fan relay control, though. Those are usually optional circuits that have to be added afterward...

 

[Arthris]

Search and you shall receive You need to order two sensors, GM CLT and IAT sensor to use speed density. And also order a 12" MSII wiring harness so you can splice into factory harness. And I would research and use the MSII Extra Firmware as ## able to do much more with it
How to MegaSquirt your 4g63 powered DSM - Eclipse, Talon, Laser

 

[VelocitàPaola]

Search and you shall receive You need to order two sensors, GM CLT and IAT sensor to use speed density. And also order a 12" MSII wiring harness so you can splice into factory harness. And I would research and use the MSII Extra Firmware as ## able to do much more with it
How to MegaSquirt your 4g63 powered DSM - Eclipse, Talon, Laser

Most of this doesn't apply... his car uses a 420A motor, not a 4G63. MS2 ECU's can read the stock CLT and IAT sensors directly; there's no need to order GM sensors.

 

[GlazedDSM]

So I can get this right, I can remove the stock pcm? How will the speed sensor and everything work? And how much do I have to rewire I.e. headlights fender harness? I do have the tach output, fan control, voltage regulater, and 4 bar map

 

[VelocitàPaola]

So I can get this right, I can remove the stock pcm?

Yes.

How will the speed sensor and everything work?

Just like they did before... You'll have to provide power to the crankshaft angle sensor, VSS, and TPS with the TPS Vref Wire and a good connection to ground. All of the gauges (with the exception of the tachometer) are connected to their own sensors, so removing the PCM doesn't affect anything.

And how much do I have to rewire I.e. headlights fender harness?

You won't have to (and shouldn't) touch any of that wiring.

 

[GlazedDSM]

I just thought i would let you know you just made my day! If it was going to be both ecus i was going to end it there but now I am so Happy to hear i can Push forward. I dont know what I would do without my fellow oh so knowledgeable DSMers. That was the only question I never seen an answer for and I really am very appreciative that you did not bash me on my simple question just from this one answer many other questions have been answered. But I must ask a couple more questions the sensors that need power such as the crankshaft angle sensor, VSS, and TPS all of these get power from the Vref? and all need grounds? and these grounds should go to ecu or chassis?

 

[low_n_slow95]

thats good news lets get to wiring!!

 

[CODE4]

But I must ask a couple more questions the sensors that need power such as the crankshaft angle sensor, VSS, and TPS all of these get power from the Vref? and all need grounds? and these grounds should go to ecu or chassis?

Yes, yes, and preferably the sensors should ground on the same lug as the MegaSquirt grounding point to avoid any ground plane differences.

 

[low_n_slow95]

ok wiring the sensors seem pretty easy. when i was looking at the schematic that came with the ms it had a constant 12v and an ignition 12v. i was gonna jump those of the radio wires, is that acceptable or will it create problems with blowing fuses?

 

[VelocitàPaola]

ok wiring the sensors seem pretty easy. when i was looking at the schematic that came with the ms it had a constant 12v and an ignition 12v. i was gonna jump those of the radio wires, is that acceptable or will it create problems with blowing fuses?

What? The TPS, VSS, and CkS need +5V to +8V. I already told you, use the +5V TPS Vref wire in your MegaSquirt harness for those. The CLT and IAT don't need a discrete power source.

 

[low_n_slow95]

Ok I must have read the diagram wrong.

 

[GlazedDSM]

Paola I understand this is frustrating to have people so mislead by MS but low and slow 95 is my PIC and not me his questions are his own. This to me has become a very useful thread I hope it aids others. So an example of power source for the IAT and CLT would be something that receives power when ignition is on run/start?

 

[Arthris]

Paola I understand this is frustrating to have people so mislead by MS but low and slow 95 is my PIC and not me his questions are his own. This to me has become a very useful thread I hope it aids others. So an example of power source for the IAT and CLT would be something that receives power when ignition is on run/start?

Dont do that. You will blow the sensors out. They need a 5vrefgood sifnal out of the ecu. The ground side of the sensor will be back at the ecu. On pin 19 i think. When i get back home ill link some sites that will show what to do

 

[VelocitàPaola]

Paola I understand this is frustrating to have people so mislead by MS but low and slow 95 is my PIC and not me his questions are his own. This to me has become a very useful thread I hope it aids others.

I know you're different people, but I wrote the information in a public thread for everyone to see.

So an example of power source for the IAT and CLT would be something that receives power when ignition is on run/start?

No, they aren't powered sensors like the rest, they're just thermistors. There are only two wires coming from each. You connect one of the wires to your MegaSquirt ECU and the other to chassis ground.

 

[GlazedDSM]

I know you're different people, but I wrote the information in a public thread for everyone to see.


No, they aren't powered sensors like the rest, they're just thermistors. There are only two wires coming from each. You connect one of the wires to your MegaSquirt ECU and the other to chassis ground.

I apologize for the confusion. I understand now that the temp sensors require no power. It didnt even cross my mind the actual temperature part of it

 

[GlazedDSM]

So I finally decided to try and go through with this in the attempt of trying to remove the stock ecu I found out that the harness for the engine goes inside of the car I stripped the wire looms off and they are all connected by little white blocks... pulled the engine to try and strip farther to remove some sensors and no luck now I have reached the point of no return I hope there is good news saying inside the car there is just a clip to undo and its all over. What I am trying to get at is all I have accomplished is making a mess of the harness in attempts to remove the stock ecu. Someone who has installed megasquirt that removed their stock ecu please tell me your steps on how you went about doing so.. I am at a loss

 

[Slo2gen]

The stock engine harness runs behind the radio and underneath the drivers seat. Unplug all that and then you should be able to pull it through into the engine bay on the passenger side, from there its as easy as unplugging stuff. If your having this much trouble just removing the harness I hope you have a good plan already set in motion on finishing the MS install.

 

[Arthris]

Are you rewiring the the harnes? using the one off the site? You could of spliced into the old harness for everything you need

 

[GlazedDSM]

My plans were to remove the stock ecu, was I suppose to just leave the clips and extra wires that just dangle? I was only trying to remove things I didn't need for megasquirt

 

[bryanwheat]

I would just use the oem harness or the megasquirt. Unless you extend the wires into the car from the ecu connector than you will have to keep the megasquirt under the hood.

 

[GlazedDSM]

So I'm supposed to just let all the wires that went to the stock ecu just hang? I plan on using the oem harness for everything except what the megasquirt controls but I already took the clips apart that went to the oem ecu I'm trying to seperate everything that MS controls from the harness so the harness for MS would be seperate from the stock harness

 

[bryanwheat]

So I'm supposed to just let all the wires that went to the stock ecu just hang? I plan on using the oem harness for everything except what the megasquirt controls but I already took the clips apart that went to the oem ecu I'm trying to seperate everything that MS controls from the harness so the harness for MS would be seperate from the stock harness

No, you use the oem engine harness with the megasquirt. Where it unhooked from the stock ecu, you will have to cut the plugs off and hook them up to the relay board on the megasquirt.