LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2004 >> CTS Base, 3.6 7 >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 15 (Engine Controls - 2.6L & 3.2L - Diagnosis (DTC P2096 - P2636)) >> Diagnostic Trouble Codes >> DTC P2176 >> Test Description

Test Description

WARNING: This page is about a different variant/trim than selected.

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

  1. 4:  The throttle valves are spring loaded in a slightly open position and should move in either direction without binding. The throttle valves should always be under spring pressure.
  2. 7:  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 P2176

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module (ECM) Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2 Observe the DTC information with a scan tool.
Are DTCs P0121, P0122, P0123, P0221, P0222, P0223 also set?		 - Go to Diagnostic Trouble Code (DTC) List Go to Step 3 
3
  1. Perform the idle learn procedure. Refer to Idle Learn Procedure .
  2. Clear the DTCs with a scan tool.
  3. Turn OFF the ignition for 30 seconds.
  4. Start the engine.
  5. 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 DTC P2176 fail since code clear?		 - Go to Step 4  Go to Step 14 
4 
  1. Turn OFF the ignition.
  2. Visually inspect the throttle body for the following conditions:
    • Throttle valves that are NOT in the rest position
    • Throttle valves that are binding open or closed
    • Throttle valves that are free to move open or closed WITHOUT spring pressure. Refer to Diagnostic Aids.
Did you find any of these conditions with the throttle body?		 - Go to Step 12  Go to Step 5 
5
IMPORTANT: Disconnecting the throttle body connector will cause additional codes to set.
  1. Disconnect the throttle body connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage of the TAC motor control 1 and the TAC motor control 2 circuits of the throttle actuator motor with a DMM connected to ground.
Is the voltage within the specified range for both circuits?		 2.5-4.5 V Go to Step 7  Go to Step 6 
6 Is the voltage less than the specified value for either circuit? 2 V Go to Step 9  Go to Step 8 
7 
  1. Turn OFF the ignition.
  2. Connect the test lamp between the TAC motor control 1 and the TAC motor control 2 circuits.
  3. Observe the test lamp as you turn ON the ignition.
Does the test lamp flash ON and then turn OFF?		 - Go to Step 10  Go to Step 11 
8 Test the TAC motor control circuit that measured above the specified value for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 11 
9 Test the TAC motor control circuit that measured below the specified value for an open or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 11 
10 Test for an intermittent and for a poor connection at the throttle body harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 12 
11 Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 13 
12 Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .
Did you complete the replacement?		 - Go to Step 14  -
13 Replace the ECM. Refer to Engine Control Module (ECM) Replacement .
Did you complete the replacement?		 - Go to Step 14  -
14
  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 15 
15 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
scientia non olet · About LEMON Manuals