Where did GM hide the pcm? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72timemachine · 10-10-2018, 11:54 AM

While I have a 2007 lq4 6.0 liter engine out of a 2007 Sliverado hd, I was looking for the pcm location. Is it located next to the battery box?

I am slowly acquiring the parts I need to do a swap on my '72 c/10. From some of the research I have done so far, I believe I also need the transmission speed sensor adapter, wiring harness, pcm, accelerator pedal (this has the electronic one) and motor mount after market adapters. Anyone know if the factory (2007 Silverado hd) air filter housing and snorkel tube will fit in a 1972 c/10?

Anyone out there who has done this tell me what else I may need?

Thanks for any help.

**truckdude239** · 10-10-2018, 06:21 PM

Driver side fender inside engine compartment under a black cover

72timemachine · 10-10-2018, 07:49 PM

Thanks, I will have a look next time I am at the boneyard.

Perhaps you can answer this one as well seeing you are doing a swap yourself.
The 2007 lq4, 6.0 liter engine I have came out of a Silverado 2500hd with a manual transmission. I have bad knees so stomping on a clutch is out. I would like to get an automatic transmission mated to my engine. I would tend to think that you would need a pcm which works with an automatic transmission rather than a manual transmission, no?

**truckdude239** · 10-13-2018, 08:49 AM

Computer is the same just have to add the wires to the plugs and have the computer reprogramed

72timemachine · 10-13-2018, 11:55 PM

Thanks, I felt I might a specific pcm for that 6 speed automatic I am hunting for.

So you have to have the pcm reprogrammed to eliminate the factory anti-theft?

95 S_Trucker · 10-14-2018, 07:48 AM

Quote:

Originally Posted by 72timemachine

Thanks, I felt I might a specific pcm for that 6 speed automatic I am hunting for.

So you have to have the pcm reprogrammed to eliminate the factory anti-theft?

The 07 LQ4 is a gen III motor. They never had six speeds behind them. The pcm is only capable of controlling 4 speed automatics.

The 6 speeds came behind gen IV motors. There are few differences between the two. But it’s best if you get a matching ecm/tcm from the same vehicle.

72timemachine · 10-14-2018, 08:59 AM

Well, here's my story. I found the '07 lq4 in a boneyard minus the manual transmission which prompted my question back to the other member whether I needed a different pcm or not.

Being new to all of this, I went to Wikki to figure out what automatic transmission I needed. While I understand Wikki could be mistaken, this is why I came to that conclusion that I would need a 6 speed automatic. They received their information from the GM newsroom.

If you look under "applications" it lists Silverado hd 6.0 from 2007-2016 using the 6L90.

https://en.wikipedia.org/wiki/GM_6L80_transmission

It's predecessor being the 4L80E/4L85E and 4L60's which Wikki said ended in 2006 for Chevrolet hd trucks.

https://en.wikipedia.org/wiki/GM_4L80-E_transmission

Perhaps the truck I took the lq4 out of is a late 2006? The doors were gone and the dash was also cut out so I only had the year of the truck written on the
truck bed to go by. Thanks for the info.

95 S_Trucker · 10-14-2018, 01:06 PM

The last year for the LQ4 was 2007. And it was in a 2500hd classic. It’s a 2007 truck, but it looks just like a 2006. I will assume the 8th digit of the vin is a U.

The new style 2007 truck would have a LY6 and a 6L90E. The LY6 is a Gen IV motor.

You have a desirable motor, but the PCM cannot control a 6 speed.

https://en.m.wikipedia.org/wiki/LS_b...l-block_engine

10-10-2018, 11:54 AM	#1
72timemachine Registered User Join Date: Oct 2008 Location: los angeles ca Posts: 220	Where did GM hide the pcm? While I have a 2007 lq4 6.0 liter engine out of a 2007 Sliverado hd, I was looking for the pcm location. Is it located next to the battery box? I am slowly acquiring the parts I need to do a swap on my '72 c/10. From some of the research I have done so far, I believe I also need the transmission speed sensor adapter, wiring harness, pcm, accelerator pedal (this has the electronic one) and motor mount after market adapters. Anyone know if the factory (2007 Silverado hd) air filter housing and snorkel tube will fit in a 1972 c/10? Anyone out there who has done this tell me what else I may need? Thanks for any help.

10-10-2018, 06:21 PM	#2
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Where did GM hide the pcm? Driver side fender inside engine compartment under a black cover __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-10-2018, 07:49 PM	#3
72timemachine Registered User Join Date: Oct 2008 Location: los angeles ca Posts: 220	Re: Where did GM hide the pcm? Thanks, I will have a look next time I am at the boneyard. Perhaps you can answer this one as well seeing you are doing a swap yourself. The 2007 lq4, 6.0 liter engine I have came out of a Silverado 2500hd with a manual transmission. I have bad knees so stomping on a clutch is out. I would like to get an automatic transmission mated to my engine. I would tend to think that you would need a pcm which works with an automatic transmission rather than a manual transmission, no?

10-13-2018, 08:49 AM	#4
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Where did GM hide the pcm? Computer is the same just have to add the wires to the plugs and have the computer reprogramed __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-13-2018, 11:55 PM	#5
72timemachine Registered User Join Date: Oct 2008 Location: los angeles ca Posts: 220	Re: Where did GM hide the pcm? Thanks, I felt I might a specific pcm for that 6 speed automatic I am hunting for. So you have to have the pcm reprogrammed to eliminate the factory anti-theft?

10-14-2018, 08:59 AM	#7
72timemachine Registered User Join Date: Oct 2008 Location: los angeles ca Posts: 220	Re: Where did GM hide the pcm? Well, here's my story. I found the '07 lq4 in a boneyard minus the manual transmission which prompted my question back to the other member whether I needed a different pcm or not. Being new to all of this, I went to Wikki to figure out what automatic transmission I needed. While I understand Wikki could be mistaken, this is why I came to that conclusion that I would need a 6 speed automatic. They received their information from the GM newsroom. If you look under "applications" it lists Silverado hd 6.0 from 2007-2016 using the 6L90. https://en.wikipedia.org/wiki/GM_6L80_transmission It's predecessor being the 4L80E/4L85E and 4L60's which Wikki said ended in 2006 for Chevrolet hd trucks. https://en.wikipedia.org/wiki/GM_4L80-E_transmission Perhaps the truck I took the lq4 out of is a late 2006? The doors were gone and the dash was also cut out so I only had the year of the truck written on the truck bed to go by. Thanks for the info.

10-14-2018, 01:06 PM	#8
95 S_Trucker Registered User Join Date: Oct 2009 Location: . Posts: 2,187	Re: Where did GM hide the pcm? The last year for the LQ4 was 2007. And it was in a 2500hd classic. It’s a 2007 truck, but it looks just like a 2006. I will assume the 8th digit of the vin is a U. The new style 2007 truck would have a LY6 and a 6L90E. The LY6 is a Gen IV motor. You have a desirable motor, but the PCM cannot control a 6 speed. https://en.m.wikipedia.org/wiki/LS_b...l-block_engine



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.