• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
TAC Motor Control High | P2102 | P2102, P2119* | P2103 | P2102 |
TAC Motor Control Low | -- | P2102, P2119* | -- | -- |
*P2119 set when resistance in the circuit was less than 15 ohms |
Component | Cause | DTCs | |||||
---|---|---|---|---|---|---|---|
Throttle Body Assembly | Throttle Valve Stuck Open | P2111 | |||||
Throttle Valve Stuck Closed | P2112 | ||||||
| P2111, P2112, P2119 |
The throttle valve in the throttle body utilizes a throttle return spring to assist in positioning the throttle valve at a resting or default position. The powertrain control module (PCM) uses driver input from the accelerator pedal position (APP) sensor in order to calculate the desired throttle position. The PCM sends the desired throttle position or target value to the throttle actuator control (TAC) module. The TAC module achieves the desired throttle position by commanding the throttle control motor to position the throttle valve at the target value. The TAC module then compares the throttle position (TP) sensor 1 value to the target value. If necessary, the throttle control motor is moved slightly in order to obtain the exact target value position.
• | The duty cycle of the close command for the TAC motor is greater than 80 percent. |
• | The TAC motor current is greater than 2 amps. |
• | DTC P2111 runs continuously once the above condition has been met. |
• | The duty cycle of the open command for the TAC motor is greater than 80 percent. |
• | The TAC motor current is greater than 2 amps. |
• | DTC P2112 runs continuously once the above condition has been met. |
• | The power supply to the TAC motor is greater than 4 volts. |
• | DTC P2119 runs continuously once the above condition has been met. |
The TP voltage does not change as expected when the throttle valve is commanded CLOSED.
The TP voltage does not change as expected when the throttle valve is commanded OPEN.
The PCM determines that the throttle valve cannot be controlled in order to obtain the correct target value.
DTCs P2111, P2112, and P2119 are Type A DTCs.
The PCM enters the Fail-Safe function operating in the reduced power mode and the TP sensor angle will default to 19 percent.
DTCs P2111, P2112, and P2119 are Type A DTCs.
• | Engine acceleration will be compromised and AT downshifts delayed when operating in the Fail-safe mode. |
• | Most TAC system parameters displayed on the scan tool freeze when the MIL illuminates and the TAC DTC sets. |
• | 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. Observe the Freeze Frame/Failure Records. |
• | The throttle valve is spring loaded to a slightly open position. The throttle valve should move open and to the closed position without binding under the normal spring tension. |
• | The throttle should NOT be free to move open or closed WITHOUT spring tension. |
• | DTC P2119 can set when there is approximately 10 ohms of resistance in the TAC motor control circuits. |
Throttle Actuator Control (TAC) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
Inspect the throttle body for the following conditions:
• | A throttle valve 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 |
• | An obstruction in the throttle bore or a damaged throttle valve |
⇒ | If any condition is found, replace the throttle body. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for control module replacement, setup, and programming |