Using LS7 MAF with LQ4 Harness - pinout differences
#1
No help over on LS1Tech so I figured I'd give it a try here.
I am currently running a stock 2003 LQ4 MAF tube in my swap with a 3" stainless pipe going to a small filter. The lump is out of a 2003 Chevy Express 3500, PCM is green/blue connectors. Identical to this:

Here is what my connector looks like:

I'd like to move up to a 4" intake tube for better throttle response, which requires the use of a different MAF sensor as mine cannot be removed from the tube. So, I purchased the following:
LSX MAF Bung (weld in, aluminum)

and LS7 MAF, GM PN 15865791

It appears that although the 5 pin connector is physically the same between the LQ4 MAF and the LS7 card MAF, the pinout internally is different (according to research about this general procedure).
LS7
Pin - Wire - Circuit - Function
A - 0.35 YE - 492 - Mass Air Flow (MAF) Sensor Signal
B - 0.8 BK/WH - 451 - Ground
C - 0.5 PK - 539 - Ignition 1 Voltage
D - 0.35 TN - 2760 - Low Reference
E - 0.35 TN - 472 - Intake Air Temperature Sensor Signal
I did find this post. Halfway down is the MAF pinout for a 2005 6.0 MAF (assuming it is the same as my 2003...)
The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 2005 4.8, 5.3, 6.0 connector/pinout information
So we get:
LQ4
A-------------BK-------------------552----------Low Reference
B-------------TN-------------------472--------IAT Sensor Signal
C-----------BK/WH----------------451--------------Ground
D-------------PK-------------------439---------Ignition 1 Voltage
E-------------YE-------------------492---------MAF Sensor Signal
LS7
Pin - Wire - Circuit - Function
A - 0.35 YE - 492 - Mass Air Flow (MAF) Sensor Signal
B - 0.8 BK/WH - 451 - Ground
C - 0.5 PK - 539 - Ignition 1 Voltage
D - 0.35 TN - 2760 - Low Reference
E - 0.35 TN - 472 - Intake Air Temperature Sensor Signal
Which means I need to do the following pin swaps at my MAF connector for the PCM to read the new MAF properly:
A -> D
B -> E
C -> B
D -> C
E -> A
Can anyone confirm?
Does anyone have any input on the LS7 MAF pinout differences as compared to a stock 2003 LQ4 MAF harness? I have no problem swapping wires, just need to know what the pinouts are.
I am currently running a stock 2003 LQ4 MAF tube in my swap with a 3" stainless pipe going to a small filter. The lump is out of a 2003 Chevy Express 3500, PCM is green/blue connectors. Identical to this:
Here is what my connector looks like:

I'd like to move up to a 4" intake tube for better throttle response, which requires the use of a different MAF sensor as mine cannot be removed from the tube. So, I purchased the following:
LSX MAF Bung (weld in, aluminum)
and LS7 MAF, GM PN 15865791

It appears that although the 5 pin connector is physically the same between the LQ4 MAF and the LS7 card MAF, the pinout internally is different (according to research about this general procedure).
LS7
Pin - Wire - Circuit - Function
A - 0.35 YE - 492 - Mass Air Flow (MAF) Sensor Signal
B - 0.8 BK/WH - 451 - Ground
C - 0.5 PK - 539 - Ignition 1 Voltage
D - 0.35 TN - 2760 - Low Reference
E - 0.35 TN - 472 - Intake Air Temperature Sensor Signal
I did find this post. Halfway down is the MAF pinout for a 2005 6.0 MAF (assuming it is the same as my 2003...)
The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 2005 4.8, 5.3, 6.0 connector/pinout information
So we get:
LQ4
A-------------BK-------------------552----------Low Reference
B-------------TN-------------------472--------IAT Sensor Signal
C-----------BK/WH----------------451--------------Ground
D-------------PK-------------------439---------Ignition 1 Voltage
E-------------YE-------------------492---------MAF Sensor Signal
LS7
Pin - Wire - Circuit - Function
A - 0.35 YE - 492 - Mass Air Flow (MAF) Sensor Signal
B - 0.8 BK/WH - 451 - Ground
C - 0.5 PK - 539 - Ignition 1 Voltage
D - 0.35 TN - 2760 - Low Reference
E - 0.35 TN - 472 - Intake Air Temperature Sensor Signal
Which means I need to do the following pin swaps at my MAF connector for the PCM to read the new MAF properly:
A -> D
B -> E
C -> B
D -> C
E -> A
Can anyone confirm?
Does anyone have any input on the LS7 MAF pinout differences as compared to a stock 2003 LQ4 MAF harness? I have no problem swapping wires, just need to know what the pinouts are.
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