GM has a known poor design on the main fuse block mounted on the wheel well under the hood. This mounting location causes corrosion and fuse failure. They have know this for at least two years according to the service manager at the GMC dealership.
Two months ago I had a U0109 code they replaced my fuel pump for $860.80. Less than two months later the same code U0109 they now say the fuse block is bad and replaced it for $1,137.52. I was also getting knock sensor faults which in my opinion. Were caused when the fuel pump was acting erratically because of the intermittent electrical connections under the fuse block, causing a lean fuel mix. I believe that the knock sensor faults P0332 and the erratic fuel pump were caused by the corroded fuse block connections. If you look up code U0109 you will see that the trouble shooting not only recommends the pump replacement but also the inspection of all the connections on the buss. Having been an industrial electrician for 43.7 years I know that intermittent electrical faults are trouble some, but an auto mechanic with 20 years experience should have inspected all the electrical connections just as the manual suggests.
For gosh sakes if you type in U0109 on You Tube the first few videos take you right to the problematic fuse block for a U0109 fault code. This mechanic failed to "wiggle" the fuse block when I had the truck in the first time and the dealership did not return my replaced fuel pump for my inspection.
A D V E R T I S E M E N T S
GM has a known poor design on the main fuse block mounted on the wheel well under the hood. This mounting location causes corrosion and fuse failure. They have know this for at least two years according to the service manager at the GMC dealership.
Two months ago I had a U0109 code they replaced my fuel pump for $860.80. Less than two months later the same code U0109 they now say the fuse block is bad and replaced it for $1,137.52. I was also getting knock sensor faults which in my opinion. Were caused when the fuel pump was acting erratically because of the intermittent electrical connections under the fuse block, causing a lean fuel mix. I believe that the knock sensor faults P0332 and the erratic fuel pump were caused by the corroded fuse block connections. If you look up code U0109 you will see that the trouble shooting not only recommends the pump replacement but also the inspection of all the connections on the buss. Having been an industrial electrician for 43.7 years I know that intermittent electrical faults are trouble some, but an auto mechanic with 20 years experience should have inspected all the electrical connections just as the manual suggests.
For gosh sakes if you type in U0109 on You Tube the first few videos take you right to the problematic fuse block for a U0109 fault code. This mechanic failed to "wiggle" the fuse block when I had the truck in the first time and the dealership did not return my replaced fuel pump for my inspection.
- David P., Livonia, US