P1635 – OBD-II DTC

OBD-II DTC P1635 – Internal Vref Malfunction

DTC P1635 meaning

DTC P1635 refers to an “Internal Vref Malfunction.” This diagnostic trouble code indicates that the vehicle’s Engine Control Module (ECM) has detected a problem with the reference voltage (Vref) that is used to power various sensors and components. The Vref is crucial for the proper functioning of the vehicle’s electronic systems, and any malfunction can lead to incorrect readings and performance issues.

DTC P1635 symptoms

Common symptoms associated with DTC P1635 may include:

• Check Engine Light illuminated
• Erratic or incorrect sensor readings
• Engine performance issues, such as stalling or rough idling
• Difficulty starting the engine
• Increased fuel consumption

DTC P1635 causes

Several factors can lead to the occurrence of DTC P1635, including:

• Faulty Engine Control Module (ECM)
• Wiring issues, such as shorts or open circuits in the Vref circuit
• Defective sensors that draw excessive current
• Corroded or loose connectors
• Electrical interference from other components

DTC P1635 seriousness

DTC P1635 is considered a serious issue because it can affect the vehicle’s overall performance and reliability. If left unaddressed, it may lead to further complications, including:

• Increased emissions
• Potential engine damage
• Failure to pass emissions tests
• Inability to diagnose other related issues

How to diagnose DTC P1635

To diagnose DTC P1635, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1635 code.
2. Inspect the vehicle’s wiring and connectors related to the Vref circuit for any visible damage or corrosion.
3. Check the voltage output of the ECM to ensure it is providing the correct Vref.
4. Test the affected sensors for proper operation and current draw.
5. Perform a continuity test on the Vref circuit to identify any shorts or open circuits.

How to fix DTC P1635 step-by-step instructions

To fix DTC P1635, follow these steps:

1. Repair or replace any damaged wiring or connectors found during the diagnosis.
2. If the ECM is faulty, consider reprogramming or replacing it.
3. Replace any defective sensors that are drawing excessive current.
4. Ensure all connections are secure and free from corrosion.
5. Clear the DTC using an OBD-II scanner and test drive the vehicle to see if the code returns.

How to erase DTC P1635

To erase DTC P1635, 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 “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to verify that the code does not return.

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