PIT5171D

Bulletin No.: PIT5171D
Date: Apr-2015
Subject:
Service Stability – Traction – ABS Rear Wheel Speed DTC Or Chassis Expansion And High Speed Bus
Communication Fault
Models:
2010 - 2015 Chevrolet Equinox
2010 - 2015 GMC Terrain
With Any Combination of DTC's U0073 U0074 U1826 U1827 U18A2 U0125 C0196 C0287 C0186 C056D C0045
C0050 Symptom 00 06 3B 4A 4B 5A 39 42 54 71
This PI was superseded to update Model Years and Warranty Information. Please discard PIT5171C.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
Customers may comment on and intermittent DIC message Service Traction/Stability, ABS indicator or Service All wheel Drive.
Upon diagnostics the technician may find DTC's related to the chassis bus, or rear wheel speed sensor with U0125 00 U0074 00 U0073 and or wheel speed
sensor C0045 C0050 symptom 06 DTCs.
Other DTC U0125 U0126 C0196 SYM 5A C0710 SYM 5A or no communication with (RDM) Rear Differential Module.
Recommendation/Instructions
This may be related to an internal wire break inside the wire harness insulation to the X411 connecter due to rodents. (Location in the left rear under the
vehicle).
Several conditions and symptoms have been found to be related to a wire harness at the left rear under vehicle.
Inspect the wire harness insulation within 1 inch of the X411 before and after connecter
It may be necessary to remove the tape and conduit from the wire harness for inspection upstream from the X411 connecter.
Some Issues have been found with circuits 6105 and 6106 for chassis bus wires and serial enable circuit 5986 and 120 ohm opens in 2500 and 2501 or 6106
and 6106.
Other circuits 884, 885, 882, and 883 when related to rear wheel speed sensor codes C0045 or C0050.
During inspection you may notice chewed up conduit or a discoloration in insulation in one spot of the wire.
If you pull the wire near that area the insulation it will break exposing the broken wire and possible corrosion or rodent damage. Repair the circuit to complete the
procedure.
Diagnostic tips on intermittent Chassis Buss and High Speed LAN Buss:
Find a known good vehicle and check the ohms between 6 & 14 and 12 & 13 and voltage readings of each for comparison.
Using DVOM set to Ohms, connect meter between DLC pins 12 and 13 for chassis buss or 6 and 14 for high speed buss of DLC connecter, set the meter to
Min / Max, and wiggle the harness up and down under the left-rear areas of the connecter.
When you hear the meter beeping, check that area of the harness.
Note: Wire broken within the insulation has also been found high up in the harness X411. It will be necessary to lower the harness to gain access. Reference
the following photos:
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Damaged conduit
Wires chewed through
Warranty Information
\For wiring repairs covered under warranty, please refer to latest version of bulletin 10-00-89-005 for warranty information on wire/connector repairs.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the
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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