Circuit Description
The throttle actuator control (TAC) module contains data which is essential
for proper TAC System operation. The TAC module continuously checks the integrity
of this data. When the TAC module is unable to write or read
data to and from RAM or the TAC module is unable to correctly
read data from the flash memory or an internal TAC module processor
fault is detected, this DTC will set which .
Conditions For Running the DTC
| • | The ignition is in the crank or run position. |
| • | The ignition voltage is more than 5.23 volts. |
Conditions for Setting the DTC
| • | The TAC module determines that an internal data test did not pass. |
| • | All above conditions met for less than 1 second. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) and
the Reduced Engine Power light will be on when this diagnostic fails. |
| • | The PCM will record operating conditions at the time the diagnostic
fails. This information will be stored in the Freeze Frame and Failure
Records. |
| • | If no other TAC System DTCs are set, the TAC System will operate
in Reduced Engine Power Mode, and this DTC will be stored. If certain TAC
System DTCs are set at the same time, the TAC System will either
default to a more tightly restricted mode of operation if it is
determined that limited safe operation is possible, or command
engine shut down. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after 3 consecutive drive
trips that the diagnostic runs and does not fail. |
| • | 40 consecutive warm-up cycles has occurred |
| | A History DTC will clear after 40 consecutive warm-up cycles,
if no failures are reported by this or any other emission related
diagnostic. |
| • | A last test failed (Current DTC) will clear when the diagnostic
runs and does not fail. |
| • | PCM battery voltage is interrupted. |
| | Important: The clear DTC info function may have to be performed twice in order
to clear a throttle actuator Control System DTC.
|
Diagnostic Aids
| • | Inspect for the following conditions that may cause an intermittent: |
| - | Inadequate terminal tension |
| - | Misrouted or damaged harness |
| - | Rubbed through wire insulation |
| - | Broken wire inside the insulation |
| • | Inspect for further causes of intermittents. Refer
Symptoms
. |
| • | If a repair is completed and the DTC was cleared using a scan
tool on the same ignition cycle, the default action will not clear until an
ignition cycle has occurred. |
Test Description
The number below refers to the step number on the diagnostic table.
-
When a problem
is detected within the TAC System, more than one TAC System related DTC may
set. This is due to the many redundant tests run continuously on this
system. It is possible that locating and repairing one individual problem
may correct more than one DTC. Keep this in mind when reviewing captured
DTC info.
