P1128 – OBD-II DTC

OBD-II DTC P1128 – Throttle Position Sensor In Range But Higher Than Expected

DTC P1128 meaning

DTC P1128 indicates that the Throttle Position Sensor (TPS) is reporting a position that is within the expected range but is higher than what the Engine Control Module (ECM) anticipates. This discrepancy can affect engine performance and fuel efficiency, as the ECM relies on accurate TPS readings to manage air-fuel mixture and throttle response.

DTC P1128 symptoms

Common symptoms associated with DTC P1128 may include:

• Reduced engine performance
• Unusual engine idle behavior
• Increased fuel consumption
• Check Engine Light (CEL) illuminated
• Stalling or hesitation during acceleration

DTC P1128 causes

Several factors can lead to the triggering of DTC P1128, including:

• Faulty Throttle Position Sensor
• Wiring issues or poor connections in the TPS circuit
• Vacuum leaks affecting air intake
• Faulty ECM or software issues
• Issues with the accelerator pedal position sensor

DTC P1128 seriousness

DTC P1128 is considered a moderate issue. While it may not cause immediate engine failure, it can lead to poor engine performance and increased emissions. Ignoring this code can result in further complications, including potential damage to the engine or exhaust system over time.

How to diagnose DTC P1128

To diagnose DTC P1128, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC.
2. Inspect the Throttle Position Sensor and its wiring for damage or corrosion.
3. Check for vacuum leaks in the intake system.
4. Test the TPS with a multimeter to ensure it is functioning within specifications.
5. Examine the accelerator pedal position sensor for proper operation.
6. Review ECM software for updates or faults.

How to fix DTC P1128 step-by-step instructions

To fix DTC P1128, follow these steps:

1. Inspect and repair any damaged wiring or connectors related to the TPS.
2. Replace the Throttle Position Sensor if it is found to be faulty.
3. Address any vacuum leaks in the intake system.
4. Check and replace the accelerator pedal position sensor if necessary.
5. Reprogram or update the ECM if software issues are detected.
6. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC P1128

To erase DTC P1128, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the DTC menu on the scanner.
4. Select the option to clear or erase the codes.
5. Confirm the action and wait for the scanner to complete the process.
6. Disconnect the scanner and start the engine to verify that the code does not reappear.

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