Adding TMAP to 2.2l

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Robf

Well-Known Member
Hey fellas, I'm turbo charging my 2.2l l61 and was looking for some guidance. I'm currently doing a water to air setup using an lsj intake. I'm wanting to switch to a 2.5 bar tmap sensor in the intake manifold and piggyback my IAT from the MAF sensor to the TMAP.

All of this to be able accurately get intake air temp post turbocharged vs atmospheric air temperature

Stock harness to TMAP adapter harness
Orange black to pin 1
Green to pin 4
Grey to pin 3

Then I run a line from my maf harness pin D to pin 2 on the tmap.

Is that it? Do I have to do anything with the low reference lines between the maf and the tmap?
 
Joebob

Joebob

Goblin Guru
I started with this image that I pulled from the internet. It is NOT the MAF tan wire to cut and splice but the light blue wire (E). Also note that the pin numbers are not in numerical order.

43955
 
Joebob

Joebob

Goblin Guru
OK, Just saw you wiring table and it seems for the 2007 it is the tan wire (IAT at D). for my 2008 LE5, it was the light blue wire.

From 2008 alldata site:

43963
 
Joebob

Joebob

Goblin Guru
Do you have a separate intake air temp sensor (like Beck's example)or do you have the MAF with the temperature built in (like what I have shown from Alldata)? I originally followed the internet picture and when started the intake temp read 32F as it was spliced with the low reference. once I changed to pin E or the last wire on the connector, I got readings that matched the ambient sensor. I actually used WAGO connectors to temp splice everything until I was sure it was right.

43970
 
R

Robf

Well-Known Member
Joebob said:
Do you have a separate intake air temp sensor (like Beck's example)or do you have the MAF with the temperature built in (like what I have shown from Alldata)? I originally followed the internet picture and when started the intake temp read 32F as it was spliced with the low reference. once I changed to pin E or the last wire on the connector, I got readings that matched the ambient sensor. I actually used WAGO connectors to temp splice everything until I was sure it was right.

View attachment 43970
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I belive my maf and iat sensor are all in one. But I have two brown wires instead of the blue. Unfortunately I don't have all data for my exact year and model to be 100 percent sure of wire selection. I'll have to wire them up and see what my temp sensor reads
 
Joebob

Joebob

Goblin Guru
That is what I did and ran it before taping everything back together. It will run, and you should see the temps if wired correctly or not before starting the engine. do you have HP tuners to scan?

Joe
 
R

Robf

Well-Known Member
Joebob said:
That is what I did and ran it before taping everything back together. It will run, and you should see the temps if wired correctly or not before starting the engine. do you have HP tuners to scan?

Joe
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Yes I have hp tuners. Unfortunately I'm not a tuner and I've changed a lot since zzp did my supercharger tune.I have enough knowledge to destroy my engine. I should be able to read IAT with ignition on.

Added k04 instead of m62 with 3.1 pulley.
Added 272 cams
New aem85 fuel pump
Boost referenced fuel system.
80lb injectors instead of 60s
2.5 bar tmap instead of 4 bar map.

I haven't attempted to start it since I haven't adjusted the tune yet. I have a dyno session on the 27th. Hoping to hear back from my tuner to see if I can get a remote idle tune before cranking it over.
 
G

Gtstorey

Goblin Guru
Your wiring is probably the same as the 2006 found here. (2) Wiring Schematics - 2006 / 2010 Cobalt/G5 LS, LT, GT, SS - LE5, LNF, LSJ, LAP, L61 | DF Kit Car Forum, post 2, engine performance.

Low reference is the internal "ground" circuit for the ecm. I'm having trouble following what connectors and wiring you are changing too, but it looks like your proposed TMAP sensor shares this low reference for both MAP and Temp. You may need to make sure this is low reference is landed back to the pin for the original temp from the TMAF. I say may because there is a chance it's the same ground bar in the ECM and could be just ran through the MAP low ref.

There is also the chance this is a monitored ground and would know that there isn't anything connected and throw a check engine code if it isn't connected. Hard to say, since none of the wiring diagrams show anything internal to the ECM, and GM may not have included that on their wiring diagrams in the 2006/2007 time period.
 
R

Robf

Well-Known Member
Gtstorey said:
Your wiring is probably the same as the 2006 found here. (2) Wiring Schematics - 2006 / 2010 Cobalt/G5 LS, LT, GT, SS - LE5, LNF, LSJ, LAP, L61 | DF Kit Car Forum, post 2, engine performance.

Low reference is the internal "ground" circuit for the ecm. I'm having trouble following what connectors and wiring you are changing too, but it looks like your proposed TMAP sensor shares this low reference for both MAP and Temp. You may need to make sure this is low reference is landed back to the pin for the original temp from the TMAF. I say may because there is a chance it's the same ground bar in the ECM and could be just ran through the MAP low ref.

There is also the chance this is a monitored ground and would know that there isn't anything connected and throw a check engine code if it isn't connected. Hard to say, since none of the wiring diagrams show anything internal to the ECM, and GM may not have included that on their wiring diagrams in the 2006/2007 time period.
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So looking at those schematics it appears MAF pin E is actually the sensor signal and D is the low reference.

So I followed this diagram and now my tmap temperature is reading as it should.

Now that I got that sorted whats the easiest way to determine if my atock harness is wired correctly with my 2.5bar tmap?
 

Attachments

R

Robf

Well-Known Member
Gtstorey said:
Some where around 101kpa key on engine off. Have you changed the settings in the tune?
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I haven't changed the tune yet. It's above my knowledge level in fear I'll damage something I leave it to people that know what they are doing. I'm learning some but not there yet.

If I remember right I had to use a 4bar previously now it's 2.5 bar. On hp tuners I'm showing 13.1 psi for atmospheric pressure. Which seems a tad low unless it's due to needing my map recalibrated
 
G

Gtstorey

Goblin Guru
If you changed the map you have to change the linear and offset into the tune. If you search the hpt forum with the part number of the maf you will likely find the values for it.
 
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Robf

Well-Known Member
Gtstorey said:
If you changed the map you have to change the linear and offset into the tune. If you search the hpt forum with the part number of the maf you will likely find the values for it.
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I changed the line to 250kpa and the offset to 9.8 from numbers I found online. Wrote it in. When checking with a multimeter I'm not showing any volts on the 5v ref wire which is grey. On HP tuners I searched pid list and I don't have one for volts for the map. I do have
Manifold vacuum 0.7psi
Intake manifold absolute pressure 1.3psi
Barometric pressure of 13.1 psi.
Any other suggestionsas to why I don't have power?
 
Ross

Ross

Goblin Guru
Get a wiring diagram for your L61 engine, and trace the grey wire back to the power source... the ECU?
My LSJ has two 5V systems, and each leg of 5V has multiple sensors on it. If there is a problem on any of the sensors, the entire 5V leg can be drawn down to 0V. Not sure if you have 1 bad grey wire, or a bad sensor somewhere on the 5V leg.
 
R

Robf

Well-Known Member
Ross said:
Get a wiring diagram for your L61 engine, and trace the grey wire back to the power source... the ECU?
My LSJ has two 5V systems, and each leg of 5V has multiple sensors on it. If there is a problem on any of the sensors, the entire 5V leg can be drawn down to 0V. Not sure if you have 1 bad grey wire, or a bad sensor somewhere on the 5V leg.
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Oh get this unsure if you were aware but you actually have to plug in the harness for it to work....
 
Ross

Ross

Goblin Guru
Good point. Plugging in the sensor will actually help the sensor work. Sometimes those connectors hide.
 
A

ah.b.normal

Goblin Guru
Ross said:
Good point. Plugging in the sensor will actually help the sensor work. Sometimes those connectors hide.
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Who Knew?o_O Actually!, a very big Thank You for fessing up! Sometimes our egos get in the way and the forum never gets the actual solution stated. Making the entire posting into a dead end rabbit hole mystery; which in turn, helps no one. So thanks Again! Others, including my self, benefit from the "true resolution" of your problem! BTW, you are not the first and will not be the last to have had this sort of trouble with the exact same remedy! I can't say when I last pulled virtually that same stunt but I'd bet it wasn't long ago. And it probably will not be too long before I do it to myself again! ;) So many problems are traced to the usual suspect, that loose nut behind the wheel.
"The man that never made a mistake likely made very little!" Quote: either Plato or Henry Ford?
 
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