DTC P2122, P2123, P2127, P2128, or P2138 (LUJ)
Diagnostic Instructions
DTC Descriptors
| DTC P2122 00: Accelerator Pedal Position (APP)
Sensor 1 Circuit Low Voltage |
| DTC P2123 00: Accelerator Pedal Position (APP)
Sensor 1 Circuit High Voltage |
| DTC P2127 00: Accelerator Pedal Position (APP)
Sensor 2 Circuit Low Voltage |
| DTC P2128 00: Accelerator Pedal Position (APP)
Sensor 2 Circuit High Voltage |
| DTC P2138 00: Accelerator Pedal Position (APP)
Sensors 1-2 Not Plausible |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Accelerator Pedal Position (APP) Sensor 1 5V Reference
|
P06A3 00, P2122 00
|
P2122 00, P2128 00
|
P06A3 00, P2135 00
|
P2138 00
|
Accelerator Pedal Position (APP) Sensor 2 5V Reference
|
P0107 00, P0697 00
|
P2127 00, P2138 00
|
P0106 00, P0108 00, P0697 00
|
P2138 00
|
Accelerator Pedal Position (APP) Sensor 1 Signal
|
P2122 00
|
P2122 00, P2138 00
|
P06A3 00, P2123 00
|
P2138 00
|
Accelerator Pedal Position (APP) Sensor 2 Signal
|
P2122 00
|
P2122 00, P2138 00
|
P06A3 00, P2123 00
|
P2138 00
|
Accelerator Pedal Position (APP) Sensor 1 Low Reference
|
-
|
P2123 00, P2138 00
|
-
|
P2138 00
|
Accelerator Pedal Position (APP) Sensor 2 Low Reference
|
-
|
P2128 00, P2138 00
|
-
|
P2138 00
|
|
| |
Typical Scan Tool Data
APP Sensor 1 and 2
Circuit
|
Short to Ground
|
Open
|
Short to Voltage
|
Operating Conditions: The engine is
operating at idle
Parameter Normal Range: APP Sensor
1-0.88-1.08 V
Parameter Normal Range: APP Sensor
2-0.39-0.59 V
|
APP Sensor 1 5V Reference
|
0.00 V
|
0.00 V
|
2.75 V
|
APP Sensor 2 5V Reference
|
0.00 V
|
0.00 V
|
1.35 V
|
APP Sensor 1 Signal
|
0.00 V
|
0.00 V
|
4.98 V
|
APP Sensor 2 Signal
|
0.00 V
|
0.00 V
|
4.98 V
|
APP Sensor 1 Low Reference
|
-
|
4.96 V
|
-
|
APP Sensor 2 Low Reference
|
-
|
4.92 V
|
-
|
|
| |
Circuit/System Description
The accelerator pedal assembly contains 2 accelerator pedal
position (APP) sensors. The APP sensors are mounted to the
accelerator pedal assembly and are not serviceable. The APP sensors
provide a signal voltage that changes relative to pedal position.
The engine control module (ECM) supplies each APP sensor with a 5 V
reference circuit, a low reference circuit, and a signal
circuit.
Both the APP sensors 1 and 2 signal percentages increase as the
pedal is depressed, from approximately 0% at rest to above 95% when
fully depressed.
Conditions for Running the DTC
P2122 00, P2123 00, P2127 00, P2128 00
| • |
DTC P06A3 00 or P0697 00 are
not set. |
| • |
The ignition is ON or the
engine is operating. |
| • |
The ignition voltage is
greater than 6 V. |
| • |
The ECM is not commanding
reduced power. |
| • |
The DTCs run continuously when
the above conditions are met. |
P2138 00
| • |
DTCs P06A3 00, P0697 00, P2122
00, P2123 00, P2127 00, or P2128 00 are not set. |
| • |
The ignition is ON or the
engine is operating. |
| • |
The ignition voltage is
greater than 6 V. |
| • |
The ECM is not commanding
reduced power. |
| • |
The DTC runs continuously when
the above conditions are met. |
Conditions for Setting the DTC
P2122 00
The ECM detects that the APP sensor 1 voltage is less than 0.46 V
for less than 1 s.
P2123 00
The ECM detects that the APP sensor 1 voltage is greater than 4.7 V
for less than 1 s.
P2127 00
The ECM detects that the APP sensor 2 voltage is less than 0.32 V
for less than 1 s.
P2128 00
The ECM detects that APP sensor 2 voltage is greater than 2.64 V
for greater than 0.5 s.
P2138 00
The ECM detects that APP sensor 1 and APP sensor 2 disagree greater
than 10% for less than 1 s.
or
The ECM detects that both APP sensor 1 and APP sensor 2 are 5%
greater than the learned minimum position for less than 1 s.
Action Taken When the DTC Sets
| • |
DTCs P2122 00, P2123 00,
P2127, 00 and P2128 00, and P2138 00 are Type C DTCs. |
| • |
DTC P2138 00 is a Type B
DTC. |
| • |
The ECM commands the throttle
actuator control system to operate in reduced engine power
mode. |
Conditions for Clearing the DTC
| • |
DTCs P2122 00, P2123 00,
P2127, 00 and P2128 00, and P2138 00 are Type C DTCs. |
| • |
DTC P2138 00 is a Type B
DTC. |
Diagnostic Aids
| • |
If a shared 5 V reference
circuit is shorted to ground or shorted to a voltage, other 5 V
reference circuits may be affected. |
| • |
The scan tool 5 V reference
parameter should display between 4.8-5.2 V. |
| • |
A high resistance condition on
the accelerator pedal position (APP) sensor circuits may cause a
DTC to set. |
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
| 1. |
Ignition ON, observe the DTC
information with a scan tool. Verify DTCs P0697 00 or P06A3 00 are
not set. |
| 2. |
Ignition ON, observe the scan
tool APP Sensor 1 and 2 Indicated parameters. Both parameters
should be 0%. |
| 3. |
Observe the scan tool APP
Sensor 1 and 2 Agree/Disagree parameter while performing the
following tests: |
| |
• |
Rapidly depress the
accelerator pedal from the rest position to the wide open throttle
position (WOT) and release pedal. Repeat the procedure several
times. |
| |
• |
Slowly depress the accelerator
pedal to WOT and then slowly return the pedal to closed throttle.
Repeat the procedure several times. |
| ⇒ |
The APP sensor 1 and 2 Agree/Disagree parameter should display
Agree. |
| 4. |
Observe the DTC information
with a scan tool. DTCs P2122 00, P2123 00, P2127 00, P2128 00, or
P2138 00 should not set. |
| 5. |
Operate the vehicle within the
conditions for running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the freeze frame/failure records data. |
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
B107 Accelerator Pedal Position Sensor harness connector at the
accelerator pedal assembly. |
| 2. |
Ignition OFF for 1 min, test
for less than 5 Ω between the B107 Accelerator Pedal Position
Sensor low reference circuit terminals listed below and
earth. |
| |
• |
Low reference circuit terminal
4 |
| |
• |
Low reference circuit terminal
5 |
| ⇒ |
If greater than the specified range, test the low reference
circuit for a short to voltage, or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| 3. |
Ignition ON, test for 4.8-5.2
V between both 5 V reference circuit terminals listed below and
ground. |
| |
• |
5 V reference circuit terminal
1 |
| |
• |
5 V reference circuit terminal
2 |
| ⇒ |
If less than the specified range, test the 5 V
reference circuit for a short to ground or open/high resistance. If
the circuit tests normal, replace the K20 Engine Control
Module. |
| ⇒ |
If greater than the specified range, test the 5 V
reference circuit for a short to voltage. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 4. |
Verify the appropriate APP
sensor voltage parameter is at 0 V. |
| ⇒ |
If greater than the specified range, test the
appropriate signal circuit terminal listed below for a short to
voltage. If the circuit tests normal, replace the K20 Engine
Control Module. |
| |
• |
APP sensor 1 signal circuit
terminal 3 |
| |
• |
APP sensor 2 signal circuit
terminal 6 |
| 5. |
Install a 3 A fused jumper
wire between the appropriate signal circuit terminal listed below
and the 5 V reference circuit terminal 1 of the appropriate B107
Accelerator Pedal Position Sensor. Verify the appropriate APP
Sensor voltage parameter is greater than 4.8 V. |
| |
• |
APP sensor 1 signal circuit
terminal 3 |
| |
• |
APP sensor 2 signal circuit
terminal 6 |
| ⇒ |
If less than the specified range, test the signal
circuit for a short to ground or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| 6. |
If all circuits test normal,
replace the B107 Accelerator Pedal Position Sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
