DTC P2128
The accelerator pedal assembly
contains 2 accelerator pedal position (APP) sensors. The APP sensors are
mounted in the pedal assembly and are not serviceable. The APP sensors provide
a signal voltage that changes relative to the position of the accelerator
pedal. The engine control module (ECM) supplies a separate 5-volt reference and
low reference circuit for each of the APP sensors.
The APP sensor 1 signal voltage
increases as the pedal is depressed, from approximately 1 volt at rest to
above 2.5 volts when fully depressed. The APP sensor 2 signal voltage
decreases as the pedal is depressed, from approximately 4 volts at rest to
less than 1 volt with the accelerator pedal fully depressed.
If the ECM detects that the APP
sensor 2 signal voltage is too high, this DTC sets.
This diagnostic procedure supports
the following DTC:
DTC P2128 Accelerator Pedal
Position (APP) Sensor 2 Circuit High Voltage
Conditions
for Running the DTC
|
• |
DTCs P0601, P0602, P0603,
P0604, P0606, P0607, P0641, P0651 are not set. |
|
• |
The ignition is ON. |
|
• |
The ignition 1 voltage is
more than 5.23 volts. |
|
• |
DTC P2128 runs continuously
when the above conditions are met. |
Conditions
for Setting the DTC
The ECM detects that the APP
sensor 2 voltage is more than 4.2 volts for more than one second.
Action
Taken When the DTC Sets
Conditions
for Clearing the MIL/DTC
|
• |
Use the J 35616 Connector
Test Adapter Kit for any test that requires probing the ECM harness connector
or a component harness connector. |
|
• |
If DTCs P0700, P2122, P2128,
and P2138 are set together in various combinations, inspect the APP
sensor 1 and 2 signal circuits for being shorted together. |
|
• |
For an intermittent condition,
refer to Testing
for Intermittent Conditions and Poor Connections . |
|
Step |
Action |
Values |
Yes |
No |
|
Schematic
Reference: Engine
Controls Schematics Connector
End View Reference: Engine
Control Module (ECM) Connector End Views or Engine
Controls Connector End Views |
||||
|
1 |
Did you perform the Diagnostic
System Check - Vehicle? |
-- |
Go
to Step 2
|
|
Is the APP sensor 2 voltage
parameter more than the specified value? |
4.2 V |
Go
to Step 4
|
Go
to Step 3
|
|
Did the DTC fail this ignition? |
-- |
Go
to Step 4
|
Go to Testing
for Intermittent Conditions and Poor Connections |
|
Does the DMM indicate voltage
within the specified range? |
4.8-5.2 V |
Go
to Step 5
|
Go
to Step 10
|
|
|
Probe the APP sensor 2 signal
circuit with a test lamp connected to ground. Does the test lamp illuminate? |
-- |
Go
to Step 8
|
Go
to Step 6
|
|
|
Observe the APP Sensor 2
parameter, with the test lamp still connected to the APP sensor 2 signal
circuit. Does the scan tool indicate
voltage at the specified value? |
0 V |
Go
to Step 9
|
Go
to Step 7
|
|
|
Test the APP sensor 2 signal
circuit for an open or high resistance. Refer to Circuit
Testing and Wiring
Repairs . Did you find and correct the
condition? |
-- |
Go
to Step 16
|
Go
to Step 13
|
|
|
Test the APP sensor 2 signal
circuit for a short to voltage. Refer to Circuit
Testing and Wiring
Repairs . Did you find and correct the
condition? |
-- |
Go
to Step 16
|
Go
to Step 11
|
|
|
Test the APP sensor 2 low
reference circuit for an open or high resistance. Refer to Circuit
Testing and Wiring
Repairs . Did you find and correct the
condition? |
-- |
Go
to Step 16
|
Go
to Step 12
|
|
|
Test the APP sensor 2 5-volt
reference circuit for a short to voltage. Refer to Circuit
Testing and Wiring
Repairs . Did you find and correct the condition? |
-- |
Go
to Step 16
|
Go
to Step 11
|
|
|
Test for shorted terminals and for
a poor connection at the engine control module (ECM) harness connector. Refer
to Testing
for Intermittent Conditions and Poor Connections and Connector
Repairs . Did you find and correct the
condition? |
- |
Go
to Step 16
|
Go
to Step 15
|
|
|
Test for an intermittent and for a
poor connection at the accelerator pedal harness connector. Refer to Testing
for Intermittent Conditions and Poor Connections and Connector
Repairs . Did you find and correct the
condition? |
-- |
Go
to Step 16
|
Go
to Step 14
|
|
|
Test for an intermittent and for a
poor connection at the ECM harness connector. Refer to Testing
for Intermittent Conditions and Poor Connections and Connector
Repairs . Did you find and correct the
condition? |
|
Go
to Step 16
|
Go
to Step 15
|
|
|
Replace the accelerator pedal
assembly. Refer to Accelerator
Pedal with Position Sensor Replacement . Did you complete the replacement? |
-- |
Go
to Step 16
|
-- |
|
|
Replace the ECM. Refer to Control
Module References for replacement, setup, and programming. Did you complete the replacement? |
-- |
Go
to Step 16
|
-- |
|
Did the DTC fail this ignition? |
-- |
Go
to Step 2
|
Go
to Step 17
|
|
|
Observe the Capture Info with a
scan tool. Are there any DTCs that have not
been diagnosed? |
-- |
System
OK |
||