DTC P0122 or P0123
Diagnostic Instructions
DTC Descriptors
DTC P0122 00: Throttle Position Sensor 1
Circuit Low Voltage |
DTC P0123 00: Throttle Position Sensor 1
Circuit High Voltage |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
5V Reference
|
P0641
|
P0122
|
P0641
|
-
|
Signal
|
P0122
|
P0123
|
P0123
|
-
|
Low Reference
|
-
|
P0123
|
P0123
|
-
|
|
|
Typical Scan Tool Data
Intake Air Flow Valve Position Sensor
Circuit
|
Short to Ground
|
Open
|
Short to Voltage
|
Operating Conditions: The engine is
operating in closed loop
Parameter Normal Range: Intake Air Flow
Valve Position Sensor 4.2 V
|
5V Reference
|
0.0 V
|
0.0 V
|
5.0 V
|
Signal
|
0.0 V
|
0.0 V
|
5.0 V
|
Low Reference
|
0.0 V
|
0.0 V
|
-
|
|
|
Circuit/System Description
The throttle body assembly contains a throttle position sensor.
The throttle position sensor is mounted to the throttle body
assembly and are not serviceable. The throttle position sensor
provide a signal voltage that changes relative to throttle blade
angle. The engine control module (ECM) supplies the throttle
position sensor with a common 5 V reference circuit , a common low
reference circuit, and a signal circuit. The throttle position
sensor signal voltage decreases from greater than 4 V at idle to
less than 1 V at wide open throttle.
Conditions for Running the DTC
• |
The ignition is ON or the
engine is operating. |
• |
The ignition voltage is
greater than 7 V. |
Conditions for Setting the DTC
P0122
The ECM detects the throttle position sensor signal voltage is less
than 0.18 V for greater than 1 s or a cumulative of 10 s.
P0123
The ECM detects the throttle position sensor signal voltage is
greater than 4.6 V for greater than 1 s or a cumulative of 10 s.
Action Taken When the DTC Sets
DTCs P0122 and P0123 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0122 and P0123 are Type B DTCs.
Diagnostic Aids
If there is a condition with the throttle body sensors the ECM
defaults to reduced power mode for the entire ignition cycle, even
if the condition is corrected.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
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. DTC P0641 should not be set.
|
2. |
Clear the DTC information with
a scan tool. |
3. |
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
Q38 Throttle Body harness connector. |
|
Note: The control
module or the sensor may be damaged if the circuit is shorted to
battery positive voltage.
|
2. |
Test for less than 5 Ω
between the low reference circuit terminal 3 and ground.
|
⇒ |
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 the 5 V reference circuit terminal 1 and ground.
|
⇒ |
If less than the specified range, test the 5 V
reference circuit for a short to ground or an 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. |
Ignition ON, verify that the
scan tool Intake Air Flow Valve Position Sensor voltage parameter
is less than 0.3 V. |
⇒ |
If greater than the specified value, test the
signal circuit for a short to voltage. If the circuit tests normal,
replace the K20 Engine Control Module. |
5. |
Connect a 3 A fused jumper
wire between the 5 V reference circuit terminal 1 and the signal
circuit terminal 5. Verify the scan tool Intake Air Flow Valve
Position Sensor parameter is greater than 4.89 V. |
⇒ |
If less than the specified value, test the signal
circuit for an open/high resistance or for a short to ground. If
the circuit tests normal, replace the K20 Engine Control
Module. |
6. |
If all circuits test normal,
replace the Q38 Throttle Body. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|