Circuit Description
The engine control module (ECM) controls the throttle blades by applying a varying voltage to the throttle valve motor. The ECM monitors the actual throttle blade position using the throttle position (TP) sensor 1 and sensor 2. If the ECM cannot detect the minimum throttle position, DTC 2101 sets.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The difference between the calculated and the actual throttle position is more than a predetermined value.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records. |
| • | The control module commands the TAC system to operate in the Reduced Engine Power mode. |
| • | A message center or an indicator displays Reduced Engine Power. |
| • | Under certain conditions the control module commands the engine OFF. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | The throttle valves are spring loaded to a slightly open position. The throttle valves should be open approximately 3-5 percent. This is referred to as the rest position. The throttle valves should not be completely closed, nor should they be open any more than the specified amount. The throttle valves should move to the open and closed position WITHOUT binding under the normal spring pressure. |
| • | The scan tool has the ability to operate Throttle Control System using the special functions. Actuate the throttle valves using the Throttle Position function located in the TAC System menu. This function will operate the throttle valve through the entire range in order to determine if the throttle body and the system operate correctly. |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check-Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
2 |
Does the DTC reset? | -- | Go to Step 3 | Go to Step 16 | ||||||
3 | Observe the DTC information. Are DTCs P0122, P0123, P0222, P0223 also set? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 4 | ||||||
4 |
Important: The throttle valves are spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
Did you find any of these conditions with the throttle body? | -- | Go to Step 13 | Go to Step 5 | ||||||
5 |
Important: Disconnecting the throttle body connector will cause additional codes to set. Is the voltage less than the specified value for both circuits? | 2 V | Go to Step 6 | Go to Step 8 | ||||||
6 |
Does the DM indicate maximum voltage above the specified value? | 2 V | Go to Step 7 | Go to Step 9 | ||||||
7 |
Does the DM indicate maximum voltage above the specified value? | 2 V | Go to Step 11 | Go to Step 10 | ||||||
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 15 | Go to Step 14 | ||||||
9 | Test the TAC motor control 1 circuit 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 15 | Go to Step 12 | ||||||
10 | Test the TAC motor control 2 circuit 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 15 | Go to Step 12 | ||||||
11 | Test for an intermittent and for a poor connection at the throttle body 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 15 | Go to Step 13 | ||||||
12 | 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 15 | Go to Step 14 | ||||||
13 | Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
14 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- | ||||||
15 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 16 | ||||||
16 | 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 in Vehicle DTC Information | System OK | ||||||
