DTC P0122 or P0123
DTC P0122 or P0123 |
Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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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
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P0641
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P0122
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P0641
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-
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Signal
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P0122
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P0123
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P0123
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-
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Low Reference
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-
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P0123
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P0123
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-
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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 |
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5V Reference
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0.0 V
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0.0 V
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5.0 V
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Signal
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0.0 V
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0.0 V
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5.0 V
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Low Reference
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0.0 V
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0.0 V
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-
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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 |
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The ignition is ON or the engine is operating.
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The ignition voltage is greater than 7 V.
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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 P0121 and P0123 are Type B DTCs.
Conditions for Clearing the DTC |
DTCs P0121 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
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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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, check the diagnostic trouble code (DTC) information with a scan tool. The DTC P0641 should not be set.
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2. |
If a DTC is set, refer to
Control Module References
.
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3. |
Clear the DTC Info with a scan tool.
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4. |
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.
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Circuit/System Testing |
1. |
Ignition OFF, disconnect the Q38 Throttle Body harness connector.
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2. |
Test for less than 5 Ω between the low reference circuit terminal 3 and ground. |
3. |
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.
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4. |
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
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5. |
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.
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6. |
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.
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7. |
Ignition ON, verify that the scan tool Intake Air Flow Valve Position Sensor voltage parameter is less than 0.3 V.
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8. |
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.
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9. |
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.
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10. |
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.
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11. |
If all circuits test normal, replace the Q38 throttle body assembly.
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Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Throttle Body Assembly Replacement
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Control Module References
for Engine Control Module replacement, setup, and programming
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