Diagnostic Instructions
DTC Descriptor
DTC U0107: Throttle Actuator Control (TAC) Module Serial Data Circuit
Circuit/System Description
The throttle actuator control (TAC) module and the powertrain control module (PCM) communicate using a dedicated serial data circuit. This serial data circuit is separate from any other serial data circuit on the vehicle. Accurate transmitting and receiving
of serial data requires not only good circuit integrity, but also adequate system voltage. This diagnostic monitors the accuracy of the serial data transmitted between the TAC module and the PCM. If the PCM detects a loss of data or invalid data, or if the throttle
limit is exceeded while operating in the Reduced Engine Power mode, DTC U0107 sets.
Conditions for Running the DTC
| • | The ignition is in the Crank or Run position. |
| • | The system voltage is more than 5.23 volts. |
| • | The communication between the TAC module and the PCM must be valid. |
| • | The DTC runs continuously when the above conditions are met. |
Conditions for Setting the DTC
| • | Invalid or missing serial data messages are detected for a predetermined period of time. |
| • | The throttle limit is exceeded while operating in the Reduced Engine Power mode. |
Action Taken When the DTC Sets
| • | DTC U0107 is a Type A DTC. |
| • | The control module commands the TAC system to operate in Reduced Engine Power mode. |
Conditions for Clearing the DTC
DTC U0107 is a Type A DTC.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
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
Important: DTC U0107 sets if the battery voltage is low or the PCM is replaced or reflashed. If the customers concern is slow cranking, if the engine is not cranking because the battery voltage is low, or if the PCM was replaced
or reflashed, ignore DTC U0107. Clear any DTCs from memory that may have set from the low battery voltage condition.
- Ignition OFF for 30 seconds.
- Ignition ON. The TP Sensor 1, TP Sensor 2, APP Sensor 1, and APP Sensor 2 voltage parameters should not all read 0 volts.
- Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition OFF, disconnect the throttle body harness connector.
- Ignition OFF, test for 0 volts between the TAC module ignition 1 voltage circuit terminal 18 and ground.
| ⇒ | If greater than the specified range, repair the short to battery voltage. |
- Ignition ON, test for B+ between the TAC module ignition 1 voltage circuit terminal 18 and ground.
| ⇒ | If less than the specified range, repair the short to ground, open circuit, or high resistance condition. |
- Ignition OFF, test for less than 5 ohms between the TAC module ground circuits terminal 8 and terminal 17 and ground.
| ⇒ | If greater than the specified range, test the ground circuits for an open/high resistance. |
- Ignition ON, test for 2-5 volts between the TAC module serial data circuits terminal 7 and terminal 16 and ground.
| ⇒ | If greater than the specified range, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the PCM. |
| ⇒ | If less than the specified range, test the serial data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM. |
- If all circuits test normal, replace the throttle body assembly.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
