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Home >> Pontiac >> 2005 >> GTO Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 6.0L - DTC P0453 To DTC P2125 >> DTC Tests >> DTC P2101: Control Module Throttle Actuator Position Performance >> Test Description
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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 5:  The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 8:  When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
DTC P2101: Control Module Throttle Actuator Position Performance

Step Action Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module (ECM) Connector End Views orEngine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set? Go to Diagnostic Trouble Code (DTC) List - Vehicle Go to Step 3 
3
IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure.
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the throttle position (TP) sensor 1 and 2 angle parameters.
  3. Apply and release the accelerator pedal several times.
Does the TP sensor 1 and 2 angle parameters increase as the pedal is applied and decrease as the pedal is released?		 Go to Step 4  Go to Step 5 
4
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Start the engine.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 Go to Step 5  Go to Diagnostic Aids
5 
  1. Turn OFF the ignition.
  2. Inspect the throttle body for the following conditions. Refer to Diagnostic Aids:
    • A throttle valve that is NOT in the rest position
    • A throttle valve that is binding open or closed
    • A throttle valve that is free to move open or closed WITHOUT spring pressure
Did you find any of these conditions with the throttle body?		 Go to Step 17  Go to Step 6 
6
IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal.
  1. Disconnect the throttle body harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the throttle actuator control (TAC) motor control 1 and 2 circuits with the test lamp connected to ground.
Did the test lamp illuminate and remain illuminated on either circuit?		 Go to Step 10  Go to Step 7 
7
IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal.
Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?		 Go to Step 11  Go to Step 8 
8 
  1. Turn OFF the ignition.
  2. Connect the test lamp between the TAC motor control 1 and battery ground.
  3. Observe the test lamp as you turn ON the ignition.
Does the test lamp flash ON and then turn OFF?		 Go to Step 9  Go to Step 12 
9
  1. Turn OFF the ignition.
  2. Connect a test lamp between the TAC motor control 2 circuit and battery ground.
  3. Observe the test lamp as you turn ON the ignition.
Does the test lamp flash ON and then OFF?		 Go to Step 13  Go to Step 12 
10
  1. Turn OFF the ignition.
  2. Disconnect the ECM connector that contains the TAC motor control circuits.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground.
Does the test lamp illuminate?		 Go to Step 15  Go to Step 14 
11
  1. Turn OFF the ignition.
  2. Disconnect the ECM connector that contains the TAC motor control circuits.
  3. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.
Does the test lamp illuminate?		 Go to Step 16  Go to Step 14 
12
  1. Turn OFF the ignition.
  2. Disconnect the ECM connector that contains the TAC motor controls circuits.
  3. Test the TAC motor control 1 and 2 circuits for an open or high resistance.
  4. Repair the circuit as necessary. Refer to Wiring Repairs .
Did you find and correct the condition?		 Go to Step 19  Go to Step 14 
13 Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 19  Go to Step 17 
14 Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 19  Go to Step 18 
15 Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs .
Did you complete the repair?		 Go to Step 19  -
16 Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs .
Did you complete the repair?		 Go to Step 19  -
17 Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .
Did you complete the replacement?		 Go to Step 19  -
18 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 19  -
19
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 Go to Step 2  Go to Step 20 
20 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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