Supplying Power and Ground to PCM
05-10-2013, 07:17 AM
#1
Supplying Power and Ground to PCM 2003 Chevy Express LQ4 with matching PCM
T56
Blue and Green PCM connectors
pinouts: http://www.lt1swap.com/2004vortec_pcm.htm
all going into my 2001 540i
Few quick questions regarding feeding the GM PCM power and grounds. I have a fairly good idea about them but maybe someone can just confirm if I'm right.
Grounds:
The following just need a simple ground from the body, right?
BLUE 1
BLUE 40
BLUE 27
BLUE 67
BLUE 24
BLUE 64
Green 40
Green 1
12V Power:
These need KEY ON 12V+, correct?
OFF RUN CRANK VOLTAGE 12V BLUE 75
IGNITION VOLTAGE BLUE 19
These need constant 12V+ even when key is off, correct?
BATTERY POSITIVE VOLTAGE BLUE 57
BATTERY POSITIVE VOLTAGE BLUE 20
T56
Blue and Green PCM connectors
pinouts: http://www.lt1swap.com/2004vortec_pcm.htm
all going into my 2001 540i
Few quick questions regarding feeding the GM PCM power and grounds. I have a fairly good idea about them but maybe someone can just confirm if I'm right.
Grounds:
The following just need a simple ground from the body, right?
BLUE 1
BLUE 40
BLUE 27
BLUE 67
BLUE 24
BLUE 64
Green 40
Green 1
12V Power:
These need KEY ON 12V+, correct?
OFF RUN CRANK VOLTAGE 12V BLUE 75
IGNITION VOLTAGE BLUE 19
These need constant 12V+ even when key is off, correct?
BATTERY POSITIVE VOLTAGE BLUE 57
BATTERY POSITIVE VOLTAGE BLUE 20
05-10-2013, 09:37 PM
#4
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just an fyi,....as far as I know ( I have a 2003 gmc savanna) its the same pcm as the 99-02 trucks, not the 03 and up. Which means if your running two fans, you do not have pin 35 usable as fan control. Mine doesnt....and vans ussually got the truck left overs, so everything is a year or so behind. You can run two relays off of 42 on the blue connector or ise the ac thru a relay.
05-10-2013, 10:33 PM
#5
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I would say 'HELL YES' you definitely want to make sure that each cylinder head is independently grounded, as is the block - at least that's how I'm doing it...
But as long as you have all of the proper/correct ECM grounds electrically connected to a common point with the "block/cylinder heads/everything else" grounds, I'd think you'd be in good shape...
But as long as you have all of the proper/correct ECM grounds electrically connected to a common point with the "block/cylinder heads/everything else" grounds, I'd think you'd be in good shape...
05-11-2013, 07:18 AM
#6
I have my grounds from battery to frame in the rear of the car. From frame to the front of the car to the engine block directly, then from engine block to frame on the drivers side. All of my grounds from my harness ground directly to the frame on the drivers side. I actually have no wires connecting to the engine itself. Seems to be running fine that way.
