the harness as necessary to match the correct
routing in the photo as shown. In order to route the
IP harness branch correctly (behind the junction
block-left I/P), remove the cover from the junction
block-left I/P and unseat the junction block from the
bracket.
5. Disconnect C202. Route the harness so that it lies
between the "goalposts" of the junction block
bracket. Seat the junction block to the bracket. The
harness will now be under the junction block.
6. Secure the harness by seating the grey offset
retaining clip to the dashmat (or brown "buddy clip"
if present - usually on SUV's only).
Reconnect C202.
7. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

•

Chafed IP Wiring Harness at Left Side
Junction Block Mounting Bracket
1. Turn OFF the ignition and all accessories.
2. Disconnect the negative battery cable. Refer to
Battery Negative Cable Disconnection and
Connection in SI.
3. Remove the left side junction block. Refer to
Instrument Panel Electrical Center or Junction
Block Replacement - Left Side in SI.
4. Inspect for chafed, damaged, pinched, open or
shorted wiring at the mounting bracket.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures in SI. Protect the
harness by covering any sharp edge with butyl
tape and the harness with woven polyester
(PET) electrical tape. Secure the harness as
needed.
5. Replace the left side junction block. Refer to
Instrument Panel Electrical Center or Junction
Block Replacement - Left Side in SI.

Bulletin No.: 08-07-30-021G

March, 2012

Page 9

6. Connect the negative battery cable. Refer to
Battery Negative Cable Disconnection and
Connection in SI.
7. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Chafed Wiring Harness at Adjustable
Pedals Motor
1. Turn OFF the ignition and all accessories.

2434892

6. Lower the transmission sufficiently to provide
access to the engine wiring harness where it
routes from the engine intake manifold to the
transmission bell housing as shown.
7. Release the wiring harness conduit from the
retainers that secure it to the transmission and/or
transfer case.
2264518

2. Inspect for chafed, damaged, pinched, open or
shorted wiring at the adjustable pedals motor as
shown.
3. If the wiring is damaged, repair as needed. Refer to
Power and Signal Distribution > Wiring Systems
and Power Management > Diagnostic Information
and Procedures in SI. Protect the conduit by
covering any sharp edge with butyl tape and the
harness with woven polyester (PET) electrical
tape. Secure the harness as needed.
4. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Chafed Wiring Harness at Transmission
1. Turn OFF the ignition and all accessories.
2. Disconnect the negative battery cable. Refer to
Battery Negative Cable Disconnection and
Connection in SI.
3. Raise the vehicle. Refer to Lifting and Jacking the
Vehicle in SI.
4. Support the transmission with a transmission jack.
5. Remove the transmission support crossmember.
Refer to Transmission Support Crossmember
Replacement in SI.

2435124

Page 10

March, 2012

2435234

Bulletin No.: 08-07-30-021G

2808042

8. Examine the harness for wiring that may be
exposed outside of the conduit. Inspect all areas
for chafed, damaged, pinched, open or shorted
wiring as shown. If damage to the wiring is not
observed, then extract the wiring from the conduit
and inspect all remaining areas as needed.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures > Wiring Repairs in
SI. Protect the conduit by covering any sharp
edge with butyl tape and the harness with
woven polyester (PET) electrical tape. Secure
the harness as needed.
9. Raise the transmission as needed to install the
transmission support crossmember. Refer to
Transmission Support Crossmember Replacement
in SI.
10. Lower the vehicle.
11. Connect the negative battery cable. Refer to
Battery Negative Cable Disconnection and
Connection in SI.
12. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

3. Locate the portion of the engine wiring harness
where it branches off from the intake manifold to
the ECM in the area shown (1).

Chafed ECM Wiring Harness From
Bracket Contact Near Engine Intake
Manifold

4. Inspect the wiring harness for damage from
contact with the steel bracket (1).
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures > Wiring Repairs
in SI.
5. Cover any sharp edge on the bracket with butyl
tape and the harness with woven polyester (PET)
electrical tape.

1. Turn OFF the ignition and all accessories.
2. Remove the upper intake manifold sight shield.
Refer to Upper Intake Manifold Sight Shield
Replacement in SI.

2808049

Bulletin No.: 08-07-30-021G

March, 2012

Page 11

2808054

6. Protect the wiring harness by adding additional
conduit (2) as shown. Tape the conduit to the
harness at both ends (1,3) to prevent movement.
7. Secure the harness to the bracket with a retaining
clip (4) as needed.

2808687

4. Gently release and slightly raise the wiring
harness (2) from the run channel (1) to allow
some slack in the harness.

Chafed Wiring Harness at Rear of
Engine Intake Manifold
1. Turn OFF the ignition and all accessories.
2. Remove the upper intake manifold sight shield.
Refer to Upper Intake Manifold Sight Shield
Replacement in SI.

2808134

5. Release the wiring harness conduit from the
retainers that secure it to the rear of the engine and
at the top of the transmission bell housing.

2808697

3. Remove the retaining plate (2) that covers the
wiring harness (1) on the top of the engine intake
manifold run channel.

Page 12

March, 2012

Bulletin No.: 08-07-30-021G

8. Secure the wiring harness within the conduit as
needed.
9. Attach the wiring harness conduit to the retainers
that secure it to the rear of the engine and at the
top of the transmission bell housing.

2328025

Note: The engine intake manifold is shown removed
to provide clarity.
6. Gently pull the wiring harness (2) up from the rear
of the engine (1).
2808687

10. Secure the wiring harness (2) within the engine
intake manifold run channel (1).

2328026

Inspect for chafed (1), damaged, pinched, open or
shorted wiring. If damage is not observed, then
extract the wiring from the conduit and inspect all
of the remaining areas as needed.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures.
7. Protect the conduit by covering any sharp edges
on the engine or transmission with butyl tape and
the harness with woven polyester (PET)
electrical tape.

2808712

⇒ If the vehicle has a small engine wiring harness
bundle, secure a portion of the harness within
some conduit (1) in the area that will be covered
by the retaining plate to prevent movement.
11. Tape both ends of the conduit (1) to the wiring
harness.

Bulletin No.: 08-07-30-021G

March, 2012

Page 13

any sharp edge with butyl tape and the harness
with woven polyester (PET) electrical tape. Secure
the harness as needed.
5. Lower the vehicle.
6. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

GMLAN Terminator Resistor 2007
Vehicles
1. Turn OFF the ignition and all accessories.
2. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.

Typical Location of Terminator Resistor (1)
Short Wheel Base Vehicle

2808697

12. Install and secure the retaining plate (2) over the
top of the wiring harness bundle (1).
13. Install the upper intake manifold sight shield.
14. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Chafed Wiring Harness at Chassis
Body Mounts Left Side Frame Rail
1. Turn OFF the ignition and all accessories.
2. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.

2653761

Typical Location of Terminator Resistor (1)
Long Wheel Base Vehicle - RPO NQZ

2268656

3. Inspect the wiring harness along the left side frame
rail at the body mounts as shown for chafed,
damaged, pinched, open or shorted wiring.
4. If the wiring is damaged, repair as needed. Refer to
Power and Signal Distribution > Wiring Systems
and Power Management > Diagnostic Information
and Procedures. Protect the conduit by covering

2658551

Page 14

March, 2012

Typical Location of Terminator Resistor (1)
Long Wheel Base Vehicle - Except RPO NQZ

2658600

Note: RPO NQZ Without Auxiliary Fuel Tank.
3. On the vehicle being serviced, observe the location
of the terminator resistor. Inspect the wiring
harness leading to the terminator resistor, for
chafed, damaged, pinched, open or shorted wiring.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures. Protect the
conduit by covering any sharp edge with butyl
tape and the harness with woven polyester
(PET) electrical tape. Secure the harness as
needed.
⇒ If the wiring is not damaged, proceed to Step 4.
4. Disconnect the electrical connector from the
terminator resistor.
5. Test the terminator resistor for 110–130Ω.
⇒ If the resistance is not within the specified
range, replace the terminator resistor and
proceed to Step 6.
⇒ If the resistance is within the specified range,
connect the electrical connector to the
terminator resistor. Refer to Power and Signal
Distribution > Data Communications > Scan
Tool Does Not Communicate with High Speed
GMLAN Device OR Diagnostic Trouble Code
(DTC) List - Vehicle in SI.
6. Connect the electrical connector to the terminator
resistor. Secure the terminator resistor as needed.
7. Lower the vehicle.
8. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Data Link Resistor 1 2009 Vehicles
1. Turn OFF the ignition and all accessories.
2. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.

Bulletin No.: 08-07-30-021G

Typical Location of Data Link Resistor 1 (1)
Short and Long Wheel Base Vehicles

2658245

Typical Location of Data Link Resistor 1 (1)
Long Wheel Base HD Vehicles

2658490

3. On the vehicle being serviced, observe the location
of the data link resistor 1 (1). Inspect the wiring
harness leading to the data link resistor 1, for
chafed, damaged, pinched, open or shorted wiring.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures. Protect the
conduit by covering any sharp edge with butyl
tape and the harness with woven polyester
(PET) electrical tape. Secure the harness as
needed.
⇒ If damage is not found, proceed to Step 4.
4. Disconnect the electrical connector from the data
link resistor 1.

Bulletin No.: 08-07-30-021G

March, 2012

Page 15

5. Test the Data Link Resistor 1 for 110–130Ω.
⇒ If the resistance is not within the specified
range, replace the data link resistor 1 and
proceed to Step 6.
⇒ If the resistance is within the specified range,
connect the electrical connector to the data link
resistor 1. Refer to Power and Signal
Distribution > Data Communications > Scan
Tool Does Not Communicate with High Speed
GMLAN Device OR Diagnostic Trouble Code
(DTC) List - Vehicle in SI.
6. Connect the electrical connector to the data link
resistor 1. Secure the data link resistor 1 as
needed.
7. Lower the vehicle.
8. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Rear Chassis Mounted Data Link
Resistor 1 Chafed Wiring Harness
Causing Intermittent No/Crank and/or
Scan Tool Does Not Communicate with
High Speed GMLAN Device
1. Turn OFF the ignition and all accessories.
2. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.

2651339

3. Typical location of a data link resistor 1 (1)
mounted on the rear of the chassis.

1991762

4. Inspect the wiring harness leading to the rear data
link resistor 1, between the truck box and frame for
chafed, damaged, pinched, open or shorted wiring
as shown.
⇒ If the wiring is damaged, repair as needed.
Refer to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures. Protect the
conduit by covering any sharp edge with butyl
tape and the harness with woven polyester
(PET) electrical tape. Secure the harness as
needed. Proceed to Step 9.
⇒ If the wiring is not damaged, proceed to Step 5.
5. Disconnect the electrical connector from the data
link resistor 1.
6. Test the data link resistor 1 for 110–130Ω.
⇒ If the resistance is not within the specified
range, replace the data link resistor 1 and
proceed to Step 7.
⇒ If the resistance is within the specified range,
connect the electrical connector to the data link
resistor 1. Refer to Power and Signal
Distribution > Data Communications > Scan
Tool Does Not Communicate with High Speed
GMLAN Device OR Diagnostic Trouble Code
(DTC) List - Vehicle in SI.
7. Connect the electrical connector to the data link
resistor 1. Secure the resistor as needed.
8. Protect the conduit by covering any sharp edge
with butyl tape and the harness with woven
polyester (PET) electrical tape. Secure the harness
as needed.
9. Lower the vehicle.
10. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Page 16

March, 2012

Bulletin No.: 08-07-30-021G

Inspection of Engine Harness
Connector X109 for Backed Out or Bent
Terminals and Poor Connections

Inspection of Engine Harness
Connector X115 for Backed Out or Bent
Terminals and Poor Connections

1. Turn OFF the ignition and all accessories.
2. Locate the X109 connector. Refer to Wiring
Systems and Power Management > Component
Locator > Master Electrical Component List > X109
in SI.

1. Turn OFF the ignition and all accessories.
2. Locate the X115 connector. Refer to Wiring
Systems and Power Management > Component
Locator > Master Electrical Component List > X115
in SI.
3. Inspect the connector for the following conditions:
• Backed out terminals
• Bent pins
• Corrosion
• Poor terminal fit (use the correct test probe)
⇒ If a condition is found, repair as needed. Refer
to Wiring Systems and Power Management >
Diagnostic Information and Procedures in SI.
AND
⇒ If corrosion is found, proceed to the section of
the bulletin titled: Repairing Fretting
Corrosion to complete the repair.
4. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

2264519

3. Before disconnecting, verify the connector is fully
seated together even though the lever is locked
down as shown.
If the connector is not fully seated, repair as
needed. Refer to Power and Signal Distribution >
Wiring Systems and Power Management >
Diagnostic Information and Procedures >
Connector Repairs in SI.
4. Inspect the connector for the following conditions:
• Backed out terminals
• Bent pins
• Corrosion
• Poor terminal tension (use the correct test
probe)
⇒ If a condition is found, repair as needed. Refer
to Power and Signal Distribution > Wiring
Systems and Power Management > Diagnostic
Information and Procedures in SI.
AND
⇒ If corrosion is found, proceed to the section of
the bulletin titled: Repairing Fretting
Corrosion to complete the repair.
5. Clear any DTCs that may be present with a scan
tool and verify the proper operation of the vehicle.

Hybrid Models (HP2) Chafed Wiring
Harness Locations and Inspection of
Engine Harness Connector X150 for
Backed Out Terminals and/or Poor
Connections at Ground Locations G102