File in Section:
Bulletin No.:

Service Bulletin

Date:

06 - Engine
12-06-04-003
December, 2012

TECHNICAL
Subject:

Diagnosis and Repair - Malfunction Indicator Lamp (MIL) Illuminated, Reduced Engine
Power Message Displayed, DTC P2135 Set

Models:

2009-2011 Buick Lucerne
2006-2008 Chevrolet Malibu
2006-2011 Chevrolet Impala
2006-2009 Pontiac G6
Equipped with Engine RPO LGD, LZ4, LZ8 or LZE

Attention: If a vehicle is encountered with this condition, DO NOT replace the throttle body.
Instead follow this procedure below.

Condition
Some customers may comment on an illuminated
malfunction indicator lamp (MIL), with a Reduced
Engine Power message displayed.
The technician may observe on a scan tool
DTC P2135: Throttle Position (TP) Sensor 1-2
Correlation set as Current or in History.

Cause
This condition may be caused by the difference
between the TP Sensor 1 and TP Sensor 2 exceeding
a calibrated value for more than 2 seconds.

Correction

4. Remove the throttle body and discard the throttle
body gasket. Refer to Throttle Body Assembly
Replacement in SI.
5. Remove any loose debris and dirt from the throttle
body assembly and the TP sensor cover. Inspect
the throttle body for damage.
Caution: Do not use any solvent that contains
Methyl Ethyl Ketone (MEK). This solvent may
damage fuel system components.
6. Clean the throttle body bore and the throttle plate
using a clean shop towel with GM Top Engine
Cleaner, P/N 1052626 (in Canada, P/N 993026), or
ACDelco Upper Engine and Fuel Injector Cleaner,
P/N X66-P, or an equivalent product.

Caution: Handle the electronic throttle control
components carefully. Do not drop, or immerse any
of the electronic throttle control components in
cleaning solvents of any type.
Warning: Approved safety glasses and gloves
should be worn when performing this procedure to
reduce the chance of personal injury.
1. With a scan tool, verify that DTC P2135 is set as
Current or in History.
⇒ If DTC P2135 is set as Current or in History,
proceed to Step 2.
⇒ If DTC P2135 is not set as Current or in History,
refer to Diagnostic Trouble Code (DTC)
List - Vehicle or Symptoms - Engine Controls
in SI.
2. Turn OFF the ignition.
3. Open the hood.
Notice: If at any time during this procedure the
throttle body or the intermediate gear is dropped,
abort this procedure and REPLACE it with a new
throttle body assembly.
Copyright 2012 General Motors LLC. All Rights Reserved.

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December, 2012

Bulletin No.: 12-06-04-003

Notice: DO NOT mount the throttle body in a vise.
The throttle body can be set on the top of a soft
protected workbench area.
7. Hold the throttle body with your hand, so that the
throttle position (TP) sensor cover is facing upward
as shown.

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2908625

8. Secure a rubber band around the throttle body and
TP sensor cover as shown.
Notice: DO NOT PRY ON THE MACHINED
SEALING SURFACE OF THE THROTTLE BODY
INLET DUCT.
9. Use a flathead screwdriver to remove the clips.
Turn over the throttle body if needed. Discard the
clips.

Notice: DO NOT allow the intermediate gear to
fall out.
11. Maintain the throttle body in an upward position.
Use your thumb to maintain contact with the
intermediate gear. Place the throttle body on the
workbench.
⇒ If the intermediate gear falls out and impacts a
hard workbench surface or the floor, abort this
procedure and REPLACE with a new throttle
body assembly.

2910009

2908632

10. Hold the throttle body with your hand, so that the
TP sensor cover is facing upward. Remove the
rubber band securing the TP sensor cover. Grasp
the TP sensor cover and carefully lift it straight up
and separate it from the throttle body.

12. Inspect the TP sensor cover and verify that the TP
sensor cover gasket has remained in the TP
sensor cover as shown. Ensure that the gasket is
accounted for and remains with the old TP sensor
cover.

Bulletin No.: 12-06-04-003

December, 2012

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Page 3

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15. Place the TP sensor cover in the position as
shown. Confirm the TP sensor drive slot orientation
is aligned in the TP sensor cover as shown.
⇒ If the TP sensor drive slot orientation is not
aligned as shown, use a small flathead
screwdriver to gently rotate the TP sensor drive
slot clockwise to the wide open throttle (WOT)
position as shown.

2909872

13. Observe the TP sensor cover for missing female
throttle actuator motor terminals (1). Verify that the
female throttle actuator motor terminals have
remained in the TP sensor cover and have not
been retained on the throttle actuator motor male
terminals as shown. Discard the old TP sensor
cover, gasket and terminals.
⇒ If one or both of the TP sensor cover female
throttle actuator motor terminals have been
retained on the throttle actuator motor male
terminals, remove and discard those female
terminals.
14. Remove the new TP sensor cover from the
protective shipping wrapper.

2910009

16. Verify that the TP sensor cover gasket is secure
and properly positioned.

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December, 2012

Bulletin No.: 12-06-04-003

2910186

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18. Grasp and hold the throttle body in the upward
position. Lightly depress the intermediate gear to
verify that it is fully seated and the gears are
engaged.

2910195

Notice: The three TP sensor cover alignment tabs
are highlighted in white for identification
purposes only.
17. Verify that all three of the TP sensor cover
alignment tabs are present and are not damaged.

2909099

19. Rotate the throttle body plate to the WOT
position (1).

Bulletin No.: 12-06-04-003

December, 2012

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20. Position and evenly install the TP sensor cover (1)
to the throttle body (2). Hold the TP sensor cover in
position and for ease of the clip installation, secure
a rubber band around the throttle body and TP
sensor cover.

22. Install the remaining TP sensor cover clips in the
sequence shown.
23. Install a NEW throttle body gasket.
24. Install the throttle body, bolts and nuts. Finger
tighten the fasteners.
25. Connect the electrical connector to the
throttle body.
26. Turn ON the ignition. Clear the DTC with a
scan tool.
27. Observe the scan tool TP Sensor 1 and 2 Agree/
Disagree parameter while slowly depressing the
accelerator pedal to WOT and then slowly returning
the pedal to closed throttle. Repeat the procedure
several times. Rapidly depress the accelerator
pedal from the rest position to the wide open
throttle position (WOT) and release pedal. Repeat
the procedure several times. The TP Sensor 1 and
2 Agree/Disagree parameter should display Agree.
⇒ If TP Sensor 1 and 2 Agree/Disagree parameter
displays Agree, proceed to Step 28.
⇒ If TP Sensor 1 and 2 Agree/Disagree parameter
displays Disagree, replace the throttle body
assembly.
28. Tighten the throttle body fasteners.

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21. Install the first TP sensor cover clip (1) in the
position shown.

Tighten
The fasteners to 10 Y (89 lb in).
29. Install any remaining components that were
removed during this procedure.
30. Perform the Throttle Learn Reset Procedure. Refer
to Throttle/Idle Learn > Throttle Learn > Reset
Procedure in SI.

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December, 2012

Part Information

•

Part Number

Description

Quantity

19300180

Throttle Position
(TP) Sensor
Cover

1

•

Warranty Information
•
•
•
•

For 2006 vehicles repaired under the 2 year/
24,000 mile (40,000 km) Emissions warranty, use:
For 2006 vehicles repaired in Canada under the
3 year/60,000 km Emissions warranty, use:
For 2006 vehicles repaired under the 7 year/
70,000 mile (120,000 km) California Emission
Coverage (Code E) warranty, use:
For 2007-2009 vehicles repaired under the 5 year/
100,000 mile (160,000 km) Powertrain Coverage
(Code P) warranty, use:

Bulletin No.: 12-06-04-003

For 2010-2011 vehicles repaired under the 3 year/
36,000 mile (60,000 km) Bumper-to-Bumper
warranty (in Canada, Base Warranty
Coverage), use:
For 2010-2011 vehicles repaired under the 3 year/
50,000 mile (80,000 km) California Emission
Coverage (Code E) warranty, use:

Labor Operation

Description

Labor Time

J7949*

Throttle Position
(TP) Sensor
Cover
Replacement

1.2 hrs**

*This is a unique labor operation for bulletin use only. It will
not be published in the Labor Time Guide.
**This time includes diagnosis, throttle body removal,
cleaning and installation, TP Sensor cover replacement and
performing the Throttle/Idle Learn > Throttle Learn > Reset
Procedure.

MIDTRONICS is a registered trademark of
MIDTRONICS, INC.
Tech 2 is a registered trademark of General Motors LLC
ACDELCO is a registered trademark of General
Motors LLC

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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