Check UBEC Bolts for Electrical Concerns

Some 2019-2020 Silverado and Sierra models may have any of several electrical-related concerns, including no crank, starter engages after engine start, flickering headlamps, erratic instrument cluster gauges, or high or low system voltage. In addition, DTCs B1325, B2750, B305D, B297B, C0049, P0562, P0700, U0100, U0101, U0102, or U3006 may be set. Some conditions may be noticed more with powertrain movement, such as when accelerating or braking.

These electrical concerns may be caused by the X50A Underhood Fuse Block bolts (Fig. 20, #1) being loose. The fuse block has built-in indicators (Fig. 20, #2) next to the bolts that pop-up as the bolts are tightened to indicate that the fuse block is fully installed. In some cases, the green indicators will be popped up but the bolts may still be loose.

Fig. 20

Check the fuse block bolts for properly installation. Verify that the bolts are torqued to 53 lb.-in. (6 Nm).

– Thanks to Jim Will

Inspecting the Dipstick Tube O-Ring and Lower Oil Pan
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