Quad drivers are small chips that perform on off functions inside the Engine Control Module. If you have a code which states there is a Quad Drivers Error, you need to check the items that that particular Quad Driver is controlling. For example, the a/c compressor relay, or trans solenoids etc...
THE FUEL PUMP DRIVER MODULE IS LOCATED ABOVE AND TO THE FRONT OF THE SPARE TIRE.
below left side of instrument panel
The fuel pump driver module is located behind the passenger side rear door pillar inside the trunk under the upholstery.
located under the dash on the driver side.
It is located at the chassis under the driver side.
The airbag module is the blue module box under the dashboard near the feet of the driver.
Underneath the driver side dash.
On a 2004 GMC truck, the airbag module is located underneath the carpet at the foot of the driver's seat. It can be accessed by pulling out the driver's seat.
On my 2001, it is located behind the driver's side kickpanel.
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It's located in the trunk, driver side wall behind the mat.
A DTC #26 is a Quad Driver Module Malfunction.