DTC P2123
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 1 signal voltage is too high, this DTC sets.
This diagnostic procedure supports
the following DTC:
DTC P2123 Accelerator Pedal
Position (APP) Sensor 1 Circuit High Voltage
Conditions
for Running the DTC
|
• |
DTCs P0601, P0602, P0603, P0604,
P0606, P0607, P0641, P0651 are not set. |
|
• |
The ignition is ON or the engine
is operating. |
|
• |
The ignition 1 voltage is
more than 5.23 volts. |
|
• |
DTC P2123 runs continuously
once the above conditions are met. |
Conditions
for Setting the DTC
The APP sensor 1 voltage is
more than 2.6 volts for more than 1 second.
Action
Taken When the DTC Sets
Conditions
for Clearing the MIL/DTC
|
• |
The control module turns OFF the
malfunction indicator lamp (MIL) after 3 consecutive ignition cycles
that the diagnostic runs and does not fail. |
|
• |
A current DTC, Last Test Failed,
clears when the diagnostic runs and passes. |
|
• |
A history DTC clears after
40 consecutive warm-up cycles, if no failures are reported by this or
any other emission related diagnostic. |
|
• |
Clear the MIL and the DTC with a
scan tool. |
|
• |
Use the J 35616
Connector Test Adapter Kit for any test that requires probing the ECM harness
connector or a component harness connector. |
|
• |
For an intermittent condition,
refer to Testing
for Intermittent Conditions and Poor Connections . |
The numbers below refer to the step
numbers on the diagnostic table.
|
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
|
Go to Diagnostic
System Check - Vehicle in Vehicle DTC Information |
Is the voltage more than the
specified value? |
2.6 V |
Go
to Step 5
|
Go
to Step 3
|
|
Did the DTC fail this ignition? |
-- |
Go
to Step 13
|
Go
to Step 4
|
|
Did the DTC fail this ignition? |
-- |
Go
to Step 5
|
Go to Diagnostic Aids |
|
Is the voltage less than the
specified value? |
0.1 V |
Go
to Step 6
|
Go
to Step 10
|
|
|
Measure the voltage from the
5-volt reference circuit of the APP sensor 1 to a good ground, with a
DMM. Is the voltage more than the
specified value? |
6 V |
Go
to Step 9
|
Go
to Step 7
|
|
Notice: Do NOT use a test lamp to test the continuity of the circuit.
Damage to the control module may occur due to excessive current draw.
Is the resistance less than the
specified value? |
10 ohms |
Go
to Step 11
|
Go
to Step 8
|
|
Important: A short to voltage on the low reference circuit may cause
internal ECM damage and sensor damage.
Did you find and correct the
condition? |
-- |
Go
to Step 15
|
Go
to Step 12
|
|
|
Important: The 5-volt reference circuits are internally and externally
connected at the controller. Other sensors that share the 5-volt reference
circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt
reference circuit may isolate a shorted sensor. Review the electrical
schematic and diagnose the shared circuits and sensors. Test the 5-volt reference circuit
of the APP sensor 1 for a short to voltage. Refer to Circuit
Testing and Wiring
Repairs in Wiring Systems. Did you find and correct the
condition? |
-- |
Go
to Step 15
|
Go
to Step 12
|
|
|
Test the signal circuit of the APP
sensor 1 for a short to voltage. Refer to Circuit
Testing and Wiring
Repairs in Wiring Systems. Did you find and correct the
condition? |
-- |
Go
to Step 15
|
Go
to Step 12
|
|
|
Test for shorted terminals and
poor connections at the APP sensor. Refer to Testing
for Intermittent Conditions and Poor Connections and Connector
Repairs in Wiring Systems. Did you find and correct the
condition? |
-- |
Go
to Step 15
|
Go
to Step 13
|
|
|
Test for shorted terminals and
poor connections at the ECM. Refer to Testing
for Intermittent Conditions and Poor Connections and Connector
Repairs in Wiring Systems. Did you find and correct the
condition? |
-- |
Go
to Step 15
|
Go
to Step 14
|
|
|
Replace the accelerator pedal
assembly. Refer to Accelerator
Pedal with Position Sensor Replacement . Did you complete the replacement? |
-- |
Go
to Step 15
|
-- |
|
|
Replace the ECM. Refer to Control
Module References in Computer/Integrating Systems for replacement, setup,
and programming. Did you complete the replacement? |
-- |
Go
to Step 15
|
-- |
|
Did the DTC fail this ignition? |
-- |
Go
to Step 2
|
Go
to Step 16
|
|
|
Observe the Capture Info with a
scan tool. Are there any DTCs that have not
been diagnosed? |
-- |
Go to Diagnostic
Trouble Code (DTC) List - Vehicle in Vehicle DTC Information |
System
OK |
|