P2100
DTC P0638, P2100, P2101, or P2119 (Without LF1)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0638
- Throttle Actuator Control (TAC) Command Performance
DTC P2100
- Throttle Actuator Control (TAC) Motor Control Circuit
DTC P2101
- Throttle Actuator Position Performance
DTC P2119
- Throttle Closed Position Performance
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position.
Conditions for Running the DTCs
P0638
* The ignition is ON or the engine is operating.
* The ignition voltage is greater than 7 volts.
* DTC P0638 runs continuously once the above conditions are met for greater than 1 second.
P2100
* The ECM is active.
* DTC P2100 runs continuously once the above condition is met.
P2101
* The ignition is ON or the engine is operating.
* The ignition voltage is greater than 7 volts.
* Throttle position adaptation is not active.
* DTCs P2101 run continuously once the above conditions are met.
P2119
* DTC P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0700, P2122, P2123, P2127, P2128, or P2138 is not set.
* The ignition is ON.
* The vehicle speed is 0 km/h (0 mph).
* The engine speed is less than 40 RPM.
* The engine coolant temperature (ECT) is 5-100°C (41-212°F).
* The intake air temperature (IAT) is 5-143°C (41-290°F).
* The ignition voltage is greater than 10 volts.
* The accelerator pedal position (APP) is less than 15 percent.
* DTC P2119 runs once per ignition cycle when the above conditions are met for less than 1 second.
Conditions for Setting the DTC
P0638
* The ECM detects that the commanded duty cycle for the range test high is greater than 80 percent.
OR
* The ECM detects that the commanded duty cycle for the range test low is greater than 80 percent.
* Either condition exists for greater than 1 second, or a cumulative of 10 seconds.
P2100
The ECM detects the output circuit for the TAC motor is open, shorted to ground, or shorted to a voltage. The condition exists, then a 5 second delay for MIL ON.
P2101
The ECM detects a 4-50 percent difference between the commanded and the actual throttle plate position, dependant upon the rate of commanded throttle movement. The condition exists, then a 5 second delay for MIL ON.
P2119
The ECM determines that the throttle valve did not return to the rest position within 500 mS. The condition exists, then a 5 second delay for MIL ON.
Action Taken When the DTC Sets
* DTCs P2100, P2101, and P2119 are Type A DTCs.
* DTC P0638 is a Type B DTC
Conditions for Clearing the DTC
* DTCs P2100, P2101, and P2119 are Type A DTCs.
* DTC P0638 is a Type B DTC
Diagnostic Aids
Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) ([1][2]Electrical Diagrams)Engine Controls Schematics (LF1) ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Throttle Actuator Control (TAC) System Description (Throttle Actuator Control (TAC) System Description)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Special Tools
J 34730-405 - Injector Test Lamp
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0121, P0122, P0123, P0221, P0222, or P0223 is not set.
• If a DTC is set, refer to DTC P0121-P0123 or P0221-P0223 (Without LF1) (P0121) for further diagnosis.
2. Observe the scan tool TP sensor parameters. Verify that TP sensor 1 voltage is between 3.02-4.00 V, and TP sensor 2 voltage is between 1.00-1.86 V.
• If either TP sensor voltage is not within the specified range refer to DTC P0121-P0123 or P0221-P0223 (Without LF1) (P0121) for further diagnosis.
3. Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release the pedal. Repeat the procedure several times. DTCs P0638, P2100, P2101, or P2119 should not set.
• If a DTC P0121, P0122, P0123, P0221, P0222, or P0223 set while performing this procedure refer to DTC P0121-P0123 or P0221-P0223 (Without LF1) (P0121) for further diagnosis.
4. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTC P0638, P2100, P2101, or P2119 should not set.
• If a DTC P0121, P0122, P0123, P0221, P0222, or P0223 set while performing this procedure, refer to DTC P0121-P0123 or P0221-P0223 (Without LF1) (P0121) for further diagnosis.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Warning
Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.
1. Ignition OFF, verify the following conditions do not exist with the Q38 throttle body assembly:
* A throttle blade that is not in the rest position
* A throttle valve that is binding open or closed
* A throttle valve that opens or closes without spring pressure
• If a condition is found, replace the Q38 throttle body.
Note: Disconnecting the throttle body harness connector causes additional DTCs to set.
2. Ignition OFF, disconnect the harness connector of the Q38 throttle body.
3. Ignition ON, test for 4.0-5.0 V between the TAC motor control 1 circuit terminal B and ground.
• If voltage is greater than the specified range, test each of the motor control circuits for a short to voltage. If the circuits tests normal, replace the K20 ECM.
• If voltage is less than the specified range, test the motor control 1 circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Connect a test lamp between the TAC motor control 2 circuit terminal A and B+. The test lamp should NOT illuminate.
• If the test lamp illuminates, test the control circuit 2 for a short to ground. If the circuit tests normal, replace the K20 ECM.
5. Test for greater than 3.5 V between TAC motor control 1 circuit terminal B and TAC motor control 2 circuit terminal A.
• If the voltage is less than the specified value, test the motor control 2 circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
6. Ignition OFF, connect the J 34730-405 - injector test lamp between the TAC motor control 1 and TAC motor control 2 circuits of the Q38 throttle body harness connector. Observe the injector test lamp while turning the ignition ON for 5 seconds and then OFF. Verify the injector test lamp illuminates brightly and then turns OFF.
• If the injector test lamp does not illuminate, replace the K20 ECM.
7. If all circuits test normal, replace the Q38 throttle body.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Throttle Body Assembly Replacement (LLT) (Removal and Replacement)Throttle Body Assembly Replacement (LF1) (Removal and Replacement)
* Control Module References (Programming and Relearning) for engine control module replacement, setup, and programming