Intermittent Chevrolet no start

Chevrolet no start — intermittent issue

GM has issued a service bulletin #PIT5391A to address an intermittent Chevrolet No Crank condition on the vehicles listed below. The problem can appear as a no start, start then immediate stall and may or may not be accompanied by a check engine light and trouble codes B1370, B1325, P0650, P263A, P263B, P0513, and/or P0262B, C0364 and/or U0403. You may also see a Service 4WD warning light or hear a relay clicking.

Models affected by service bulletin #PIT5391A

2015-2016 Cadillac Escalade Models
2014 Chevrolet Silverado 1500
2015-2016 Chevrolet Silverado, Suburban, Tahoe
2014 GMC Sierra 1500
2015-2016 GMC Sierra, Yukon Models

GM has determined that these issues could be caused by loss of ignition 1 voltage. GM states that there are two KR73 ignition relays; one in the underhood fuse block and the other in the left I/P fuse block. The relays provide power to different fuses.

The loss of ignition 1 voltage may be caused by:

Either one or both ignition main relays failing to provide power to their respectable fuses.

Terminal issues at a fuse block connector where the Ignition 1 circuits exit the fuse block, (one example is circuit 439 at the underhood fuse block connector X2 terminal M7). If the problem is caused by a terminal issue, the ignition relays will activate and provide power to their respective fuses, but the power won’t flow to their fespective module/component.

Fix Chevrolet no start

Start your diagnosis by inspecting ALL the underhood fuse block connectors for any backed out terminals, poor terminal fit and/or bent/twisted terminals. GM has identified these connectors as the most prone to failure:

Terminal M5 at connector X4, for circuit 5199
Terminal M7 at connector X2 for circuit 439

Next, inspect for any backed out terminals, poor terminal fit and/or bent/twisted terminals at the Left I/P Fuse Block. GM has identified these connectors as the most prone to failure:

Terminal 42 at connector X1, for circuit 5199
Terminal 44 at connector X2, for circuit 1850

Then check circuit 5199 under the driver’s sill plate for damaged or corrosion. Repair any damaged wires.

©, 2020 Rick Muscoplat