Diagnostic Aids

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

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 .

DTC P2101

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	Perform the idle learn reset with a scan tool. Clear the DTCs with a scan tool. Turn OFF the ignition. Start the engine. 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. Does the DTC reset?	-	Go to Step 3	Go to Step 18
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. Turn OFF the ignition. 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 Did you find any of these conditions with the throttle body?	-	Go to Step 15	Go to Step 5
5	IMPORTANT: Disconnecting the throttle body connector will cause additional codes to set. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Measure the voltage of the throttle actuator control (TAC) motor control 1 and TAC motor control 2 circuits of the throttle actuator motor with a DMM connected to ground. Is the voltage less than the specified value for both circuits?	2 V	Go to Step 6	Go to Step 8
6	Turn OFF the ignition. Allow the engine control module (ECM) to completely power down. This may take several minutes and can be verified by the loss of communication with the scan tool. Connect the DMM between the TAC motor control 1 circuit and a good ground. Using the min/max function, select the proper voltage range and record the maximum voltage with a DMM. Turn ON the ignition. Does the DMM indicate maximum voltage above the specified value?	2 V	Go to Step 7	Go to Step 9
7	Turn OFF the ignition. Allow the ECM to completely power down. This may take several minutes and can be verified by the loss of communication with the scan tool. Connect the DMM between the TAC motor control 2 circuit and a good ground. Using the min/max function, select the proper voltage range and record the maximum voltage with a DMM. Turn ON the ignition. Does the DMM 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 17	Go to Step 16
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 17	Go to Step 13
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 17	Go to Step 13
11	IMPORTANT: The DMM and test leads must be calibrated to 0 ohms to prevent misdiagnosis. Refer to the DMM User Manual for the calibration procedure. Turn OFF the ignition. Disconnect the ECM connector containing the TAC motor control circuits. Measure the resistance of the TAC motor control 1 and TAC motor control 2 circuits between the ECM connector and the throttle body connector. Refer to Circuit Testing in Wiring Systems. Is the resistance less than the specified value?	4 ohm	Go to Step 12	Go to Step 14
12	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 17	Go to Step 15
13	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 17	Go to Step 16
14	Repair the TAC motor control circuit with the high resistance. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	-	Go to Step 17	-
15	Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?	-	Go to Step 17	-
16	Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 17	-
17	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Operate the vehicle with in the Conditions for Running the DTC. You may also operate the vehicle with in the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 2	Go to Step 18
18	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