Refer to Engine Controls Schematics
Control Module, Cruise Control Switch, APP Sensor
.
Circuit Description
The accelerator pedal position (APP) sensor is mounted on the accelerator
pedal assembly. The sensor is actually 3 individual APP sensors within
one housing. Three separate signals, grounds, and 5 volt
reference circuits are used in order to connect the APP sensor assembly
and the throttle actuator control (TAC) module. If only one APP
sensor DTC is set, the redundant APP systems allow the TAC system
to continue operating normally. This DTC sets if the powertrain
control module (PCM) detects a condition with more than one APP sensor.
One APP sensor DTC will not cause the REDUCED ENGINE POWER message
to be displayed. Two APP sensor DTCs for the same sensor also
will not cause the REDUCED ENGINE POWER message to be displayed.
However, if 2 or more DTCs are set involving more than one APP
sensor, this DTC will set and the REDUCED ENGINE POWER message
is displayed.
Conditions for Running the DTC
| • | No active TAC module DTCs. |
| • | The ignition switch is in the crank or run position. |
| • | The ignition voltage is more than 5.23 volts. |
Conditions for Setting the DTC
| • | Two or more APP sensors are out of range or all 3 APP sensors
disagree, or one APP sensor is out of range and the other 2 APP sensors
disagree. |
| • | All of the above conditions are met for less than 1 second. |
Action Taken When the DTC Sets
| • | The PCM stores the DTC information into memory when the diagnostic
runs and fails. |
| • | The PCM illuminates the malfunction indicator lamp (MIL) when
the diagnostic runs and fails. |
| • | The PCM records the operating conditions at the time the diagnostic
fails. The PCM stores this information in the Freeze Frame and/or Failure
Records. |
| • | The TAC system operates in reduced engine power mode. If certain
TAC system DTCs are set at the same time, the TAC system may command the
engine to shut down. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the malfunction indicator lamp (MIL) after
3 consecutive ignition cycles that the diagnostic runs and does not
fail. |
| • | A last test failed, or current DTC, clears when the diagnostic
runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles,
if no failures are reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Diagnostic Aids
Important: Remove any debris from the PCM or TAC module connector surfaces before
servicing the PCM or TAC module. Inspect the PCM or TAC module connector
gaskets when diagnosing or replacing the modules. Ensure that
the gaskets are installed correctly. The gaskets prevent contaminate
intrusion into the PCM or TAC modules.
| • | For any test that requires probing the PCM or a component
harness connector, use the J 35616
Connector Test Adapter Kit . Using this
kit prevents damage to the harness or component terminals.
Refer to
Using Connector Test Adapters
in Wiring Systems. |
| • | The following may cause an intermittent: |
| - | Rubbed through wire insulation |
| - | Broken wire inside the insulation |
| • | For an intermittent, refer to
Symptoms
. |
| • | Inspect the TAC module connectors for signs of water intrusion.
When this occurs, multiple DTCs should be set and no circuit or component
conditions can be located. |
| • | The APP sensor 1 and the TP sensor 1 5-volt reference circuits
are internally connected within the TAC module. |
| • | The APP sensor 2 and the TP sensor 2 5-volt reference circuits
are internally connected within the TAC module. |
| • | When the TAC module detects a condition 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. Locating
and repairing one individual condition may correct more
than one DTC. Keep this in mind when reviewing captured
DTC info. |
Test Description
The number below refers to the step number on the diagnostic table.
-
When the problems
are corrected which are causing the APP sensor DTCs to set, the status
of this DTC will change to History.
When the TAC module detects a problem 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. Locating and repairing one
individual problem may correct more than one DTC. Keep this in
mind when reviewing captured DTC info.
