PIP5003C

Bulletin No.: PIP5003C
Date: Feb-2013
Subject:
Intermittent Service 4wd Message In The DIC With C0387 Stored
Models:
2010-2013 Cadillac Escalade Hybrid
2010-2013 Chevrolet Tahoe Hybrid
2010-2013 Chevrolet Silverado Hybrid
2010-2013 GMC Yukon Hybrid
2010-2013 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2010-2013 GMC, Sierra, Yukon, Yukon XL
Built PRIOR to 1/1/2013 equipped with RPO NQH or NP0
This PI was superseded to update model years and administrative details. Please discard PIP5003B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Customer may comment on a service four wheel drive message displayed in the driver’s information center. Technician may find a current or history diagnostic
trouble code C0387 stored in the transfer case control module.
Recommendation/Instructions
If the diagnostic trouble code is stored current and is a hard code proceed with published diagnostics.
If diagnostic trouble code C0387 is the only code stored, is intermittent and cannot be duplicated.
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Attempt to shift the transfer case through all ranges successfully.
2.
Safely perform a test drive while in auto 4 wheel drive in conditions which will cause encoder motor actuation (slip event).
3.
If the diagnostic trouble code is intermittent and cannot be reproduced DO NOT replace the TCCM or re-flash the transfer case control module with the
same software.
As part of the diagnostics the transfer case control module monitors shift shaft position after a shift or slip correction is requested.
If the transfer case motor does not begin to move the shift shaft within 50 milliseconds of a shift request, this diagnostic trouble code can set.
Temperatures and system voltage also can have an effect on motor operation; therefore the customer should be questioned about when this condition occurs.
If the customer experiences repeat occurrences of this condition and a root cause cannot be determined, it is probable that the transfer case encoder motor is
not responding quickly enough and should be replaced.
Warranty Information
For vehicles repaired under warranty use:
Labor Operation
Description
Labor Time
K4126
Transfer Case Two/Four Wheel Drive Actuator Replacement
Use Published Labor Operation
Time
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the
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remaining steps do not need to be performed.
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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