19NA212

Bulletin No.:
Service Bulletin
Date:
19-NA-212
September, 2019
INFORMATION
Subject:
Diagnostic Tip for Crank/No Start
This bulletin replaces PIP5168. Please discard PIP5168.
Brand:
Cadillac
Model:
CTS
GMC
2016
Escalade
2015
Camaro
2016
Corvette
2014
Express
Chevrolet
Model Year:
from
2014
VIN:
to
2019
2019
from
to
Engine:
Transmission:
LT4
L86
LT1, LT4
LT1, LT4, LT5
2019
LV1, L20,
L96, LC8
Silverado
2010
Silverado LD
2019
2018
Silverado
2500/3500
2019
Silverado
1500 (New
Model)
2019
Suburban
2015
L83 L96 L86
Tahoe
2015
L83 L86
Savana
2014
2019
2018
LV3 L83 L86,
L96, LC8
2019
LV3 L82
L84 L87
LV1 L20
L96 LC8
Sierra
2010
Sierra
Limited
2019
Sierra
2500/3500
2019
Sierra 1500
(New Model)
2019
LV3 L82
L84 L87
Yukon
2015
L83 L86
LV3 L83 L86,
L96, LC8
2019
Involved Region or Country
North America
Condition
Some customers may comment that the vehicle cranks but doesn't start.
Cause
This condition may be caused by a sheared camshaft sprocket locating pin.
– The camshaft may seize to the camshaft bearings at one time during engine operation.
– On rare occasions, a crank no start may be encountered. Typically, when this occurs, it
is generally when the vehicle still has low mileage, possibly during the Pre-Delivery
inspection.
Copyright 2019 General Motors LLC. All Rights Reserved.
Page 2
Correction
September, 2019
Bulletin No.: 19-NA-212
During diagnosis, the technician will find proper fuel pressure, spark from each spark plug
wire and proper injector pulse. However, the following concerns will be noted during their
diagnosis:
• Low static compression
• Excessive cylinder leakage past an intake or exhaust valve
• The engine may start, but runs poorly if the CMP sensor is disconnected
• The valve train may not move while cranking the engine
If this concern is encountered, refer to the Service Procedure below and perform the
suggested steps as necessary.
Service Procedure
1. Crank the engine while checking for movement in
the valve train.
Note: This can be done by shining light down the oil fill
tube on most models.
• If the valve train appears to be moving normally
while the crankshaft is turning, continue to
step 2.
• If you determine valve train is not moving while
the crankshaft is turning, move ahead to step 4.
2. Disconnect the CMP sensor to see if the engine
will start.
⇒ If the engine starts, move ahead step 4.
3. Perform the following SI diagnostic procedures as
necessary:
3.1. Engine Cranks But Does Not Run diagnosis.
3.2. Engine Compression Test (document results).
3.3. Cylinder Leakage Test (document results).
⇒ If the SI procedures above isolate an engine
mechanical concern (low compression; excessive
cylinder leakage through the exhaust or intake, any
type of valve train damage, etc.), continue to step 4.
Note: Before removing the front cover, follow the latest
version of 09-06-04-026 to verify the ECM calibrations
in case engine replacement is necessary. If this is a
new dealer stock unit, it is not necessary to verify the
ECM calibrations.
4. After completing steps 1, 2, or 3, remove the front
cover to inspect for a sheared cam sprocket
locator pin.
⇒ If the cam sprocket locator pin has sheared,
engine replacement is required.
Parts Information
No parts are required for this repair.
Warranty Information
The correction for this concern may be one of several
repairs described above. For vehicles repaired under
warranty, please use the appropriate warranty labor
operation based on the actual cause and repair.
Version
1
Modified
Released September 16, 2019
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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