Info - Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due
to Installation of Alarm Systems #02-06-05-004A - (Jan 9, 2004)
Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to
Installation of Alarm Systems
2004 and Prior GM Passenger Cars and Light Duty Trucks
2003-2004 HUMMER H2
2004 and Prior Isuzu Light Duty Trucks
This bulletin is being revised to add the 2004 model year and include
specific DTCs in the title line. Please discard Corporate Bulletin Number
02-06-05-004 (Section 06 - Engine/Propulsion System).
General Motors Engineering, in an effort to determine the root cause of
catalytic converter damage, has determined that aftermarket alarm systems
incorrectly installed in vehicles have the potential to cause misfire codes
and damage to the converter. These alarm systems use a circuit interrupt
which utilizes the ignition circuit on the vehicles.
These alarm systems utilize mechanical relays and normal vehicle movement
can trigger these relays to engage and disengage the ignition circuit while
the vehicle is in motion. These disruptions of the ignition circuit, which
occur in milliseconds, may cause more fuel to be commanded. Over time, this
dumping of fuel on and off again can cause misfire codes and ultimately
damage the converter assembly.
Engineering could not identify any alarms that utilize solid state circuitry
that would eliminate this concern. Because of this, it has been determined
that all alarm systems must be routed through the starter circuit in order
to avoid this condition.
Dealers must be aware of this issue and take note of the wiring on vehicles
with alarm systems that come in for repair, particularly for catalytic
converter damage that seem to have no known root cause.
Product Safety - Windshield Wiper Motor Failure #03023 - (Oct 8, 2003)
03023 - Windshield Wiper Motor Failure
1994 Chevrolet C/K Pickup, Tahoe 4WD, Suburban 2WD
1995 Chevrolet C/K Pickup, C/K Crew Cab 4WD, Tahoe 4WD, Suburban, Astro Van
1996 Chevrolet Blazer, S10, C/K Pickup, C/K Crew Cab, Tahoe, Suburban, Astro
1997 Chevrolet S10 2WD, C/K Crew Cab, Suburban 4WD, Astro Van
1994 GMC Sierra Pickup, Yukon 4WD, Suburban 2WD
1995 GMC Sierra Pickup, Sierra Crew Cab 4WD, Yukon 4WD, Suburban, Safari Van
1996 GMC Sonoma, Jimmy, Sierra Pickup, Sierra Crew Cab, Yukon, Suburban,
1997 GMC Sonoma 2WD, Sierra Crews Cab, Suburban 4WD, Safari Van
1996 Oldsmobile Bravada
General Motors has decided that a defect which relates to motor vehicle
safety exists in certain 1994 Chevrolet C/K Pickup, Tahoe, Suburban; 1995
Chevrolet C/K Pickup, C/K Crew Cab, Tahoe, Suburban, Astro Van; 1996
Chevrolet Blazer, S10 Pickup, C/K Pickup, C/K Crew Cab, Tahoe, Suburban,
Astro Van; 1997 Chevrolet S10 Pickup, C/K Crew Cab, Suburban 4WD, Astro Van;
1994 GMC Sierra Pickup, Yukon, Suburban; 1995 GMC Sierra Pickup, Sierra Crew
Cab, Yukon, Suburban, Safari Van; 1996 GMC Sonoma, Jimmy, Sierra Pickup,
Sierra Crew Cab, Yukon, Suburban, Safari Van; 1997 GMC Sonoma, Sierra Crew
Cab, Suburban 4WD, Safari Van; 1996 Oldsmobile Bravada vehicles. These
vehicles may have a condition in which the windshield wiper motor may fail.
These failures are the result of cracked solder joints on the controller
circuit board near the wiring harness connector. Depending on which solder
joints crack or the severity of the crack, the windshield wipers could work
intermittently or not at all. If this were to occur in a severe weather
situation, driver visibility could be reduced, which could result in a
vehicle crash without prior warning.
Dealers are to replace the wiper motor circuit board and cover.
Info - Driveline Clunk Noise When Shifting Between PARK and DRIVE, PARK and
REVERSE or DRIVE and REVERSE #99-04-20-002C - (Jan 31, 2005)
Driveline Clunk Noise When Shifting Between PARK and DRIVE, PARK and REVERSE
or DRIVE and REVERSE
2005 and Prior GM Light Duty Truck Models
2003-2005 HUMMER H2
This bulletin is being revised to add model years. Please discard Corporate
Bulletin Number 99-04-20-002B (Section 04 -- Driveline/Axle).
Important: The condition described in this bulletin should not be confused
with the following previous bulletins:
. Info - Discontinue Flushing and Replacing Transfer Case Fluid
Due to Bump/Clunk Concern (Corporate Bulletin Number 99-04-21-004A or
. Clunk, Bump or Squawk when Vehicle Comes to Complete Stop or
Accelerating from Complete Stop or Accelerating from Complete Stop (Replace
Rear Drive Shaft Nickel-Plated Slip Yoke) (Corporate Bulletin Number
01-04-17-004B or newer).
Some owners of light duty trucks equipped with automatic transmissions may
comment that the vehicle exhibits a clunk noise when shifting between Park
and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of
vehicles equipped with automatic or manual transmissions may comment that
the vehicle exhibits a clunk noise while driving when the accelerator is
quickly depressed and then released.
Whenever there are two or more gears interacting with one another, there
must be a certain amount of clearance between those gears in order for the
gears to operate properly. This clearance or freeplay (also known as lash)
can translate into a clunk noise whenever the gear is loaded and unloaded
quickly, or whenever the direction of rotation is reversed. The more gears
you have in a system, the more freeplay the total system will have.
The clunk noise that owners sometimes hear may be the result of a buildup of
freeplay (lash) between the components in the driveline.
For example, the potential for a driveline clunk would be greater in a
4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This
is because in addition to the freeplay from the rear axle gears, the
universal joints, and the transmission (common to both vehicles), the
4-wheel drive transfer case gears (and their associated clearances) add
additional freeplay to the driveline.
In service, dealers are discouraged from attempting to repair driveline
clunk conditions for the following reasons:
. Comments of driveline clunk are almost never the result of one
individual component with excessive lash, but rather the result of the added
affect of freeplay (or lash) present in all of the driveline components.
Because all of the components in the driveline have a certain amount of lash
by design, changing driveline components may not result in a satisfactory
. While some owners may find the clunk noise objectionable, this
will not adversely affect durability or performance.
. For additional diagnostic information, refer to the appropriate
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