P1631 – OBD-II DTC

OBD-II DTC P1631 – Theft Deterrent Fuel Enable Signal Not Received/ B+ Supply To VCRM A/C Circuit Malfunction

DTC P1631 meaning

DTC P1631 refers to a diagnostic trouble code indicating that the theft deterrent fuel enable signal has not been received by the vehicle’s control module. This code is often associated with issues in the vehicle’s anti-theft system, which can prevent the engine from starting. Additionally, it may indicate a malfunction in the B+ supply to the Vehicle Control Relay Module (VCRM) or the air conditioning circuit.

DTC P1631 symptoms

Common symptoms associated with DTC P1631 may include:

• Engine not starting
• Security or anti-theft warning light illuminated on the dashboard
• Intermittent starting issues
• Loss of power to certain electrical components

DTC P1631 causes

Several factors can lead to the triggering of DTC P1631, including:

• Faulty ignition switch
• Malfunctioning anti-theft system
• Wiring issues or poor connections in the fuel enable circuit
• Defective Vehicle Control Relay Module (VCRM)
• Low battery voltage or poor battery condition

DTC P1631 seriousness

DTC P1631 is considered a serious issue as it can prevent the vehicle from starting, leaving the driver stranded. It may also indicate underlying problems with the vehicle’s security system, which could lead to further complications if not addressed promptly.

How to diagnose DTC P1631

To diagnose DTC P1631, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC P1631.
2. Check for any additional trouble codes that may provide more context.
3. Inspect the vehicle’s battery and charging system for proper voltage and connections.
4. Examine the wiring and connectors related to the anti-theft system and VCRM for damage or corrosion.
5. Test the ignition switch for proper operation.
6. Verify the functionality of the Vehicle Control Relay Module (VCRM).

How to fix DTC P1631 step-by-step instructions

To fix DTC P1631, follow these steps:

1. Address any battery or charging system issues by replacing a weak battery or repairing charging system faults.
2. Repair or replace damaged wiring or connectors related to the anti-theft system and VCRM.
3. If the ignition switch is faulty, replace it with a new one.
4. Test and, if necessary, replace the Vehicle Control Relay Module (VCRM).
5. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC P1631

To erase DTC P1631, 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 vehicle to check if the code returns.

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