Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC P2118: Throttle Actuator Control Motor Current PerformanceDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
TAC Motor Control High | P2102 | P2102 | P2103 | P2102 |
TAC Motor Control Low | P2103 | P2102 | P2103 | P2102 |
ETCS Ignition 1 Voltage | P2118 | P2118 | -- | -- |
Circuit/System Description
The powertrain control module (PCM) operates the motor in the throttle actuator control (TAC) module assembly that controls throttle plate movement in the throttle body. The PCM receives battery voltage to operate the TAC motor from the electronic throttle control system (ETCS) fuse circuit.
Conditions for Running the DTC
| • | The ignition is ON or the engine is running. |
| • | The DTC runs continuously once the above condition has been met. |
Conditions for Setting the DTC
The ETCS battery voltage supply to the PCM is less than 4 volts for greater than 1 second.
Action Taken When the DTC Sets
| • | DTC P2118 is a Type A DTC. |
| • | The PCM enters the Fail-Safe function operating in the Reduced Engine Power Mode. The throttle valve return spring will close the throttle valve to the idle position with the TP sensor 1 angle defaulted to 19 percent. |
Conditions for Clearing the DTC
DTC P2118 is a Type A DTC.
Diagnostic Aids
TAC Motor Current is displayed on the scan tool, but the displayed value freezes when the MIL illuminates and the DTC sets.
Engine acceleration will be compromised and AT downshifts delayed when operating in the Reduced Engine Power Mode.
Reference Information
Schematic Reference
Description and Operation
Throttle Actuator Control (TAC) System Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Verify that the ETCS fuse is not open.
- Engine running, observe the DTC information with a scan tool. DTC P2118 should not set.
- 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: Refer to Electric Coolant Fan Warning in the Preface section.
- Ignition OFF, disconnect the X1 harness connector at the PCM.
- Ignition ON, verify a test lamp illuminates between the ETCS B+ circuit terminal X1-3 and ground.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for control module replacement, setup, and programming
