P1636 – OBD-II DTC

OBD-II DTC P1636 – Theft Deterrent Start Enable Signal Not Correct/ Main Relay Malfunction (Power Hold)

DTC P1636 meaning

DTC P1636 refers to a diagnostic trouble code indicating a problem with the theft deterrent system in a vehicle. Specifically, it signifies that the start enable signal is not correct, which may prevent the engine from starting. This code can also be associated with a malfunction in the main relay, which is responsible for maintaining power to critical systems when the vehicle is in operation.

DTC P1636 symptoms

Common symptoms associated with DTC P1636 may include:

• Engine will not start
• Intermittent starting issues
• Dashboard warning lights illuminated
• Security system activation without reason
• Loss of power to certain electrical components

DTC P1636 causes

Several factors can lead to the triggering of DTC P1636, including:

• Faulty ignition switch
• Malfunctioning main relay
• Wiring issues or poor connections in the theft deterrent system
• Defective body control module (BCM)
• Issues with the vehicle’s key or key fob

DTC P1636 seriousness

DTC P1636 is considered a serious issue as it can prevent the vehicle from starting, leaving the driver stranded. Additionally, it may indicate underlying problems with the vehicle’s electrical system or security features, which could lead to further complications if not addressed promptly.

How to diagnose DTC P1636

To diagnose DTC P1636, follow these steps:

• Use an OBD-II scanner to confirm the presence of the code.
• Check for any additional trouble codes that may provide more context.
• Inspect the vehicle’s wiring and connectors related to the ignition and theft deterrent system.
• Test the main relay for proper operation.
• Examine the ignition switch for faults.
• Verify the functionality of the key or key fob.

How to fix DTC P1636 step-by-step instructions

To fix DTC P1636, follow these step-by-step instructions:

1. Clear the DTC using an OBD-II scanner.
2. Inspect and repair any damaged wiring or connectors related to the ignition and theft deterrent system.
3. Replace the main relay if it is found to be faulty.
4. Test and replace the ignition switch if necessary.
5. Check the key or key fob for proper functionality and replace if needed.
6. Re-scan the vehicle to ensure the code does not return.

How to erase DTC P1636

To erase DTC P1636, follow these steps:

• Connect an OBD-II scanner to the vehicle’s diagnostic port.
• Turn the ignition key to the “On” position without starting the engine.
• Access the scanner’s menu and select the option to clear or erase trouble codes.
• Confirm the action and wait for the scanner to complete the process.
• Disconnect the scanner and start the vehicle to check if the code reappears.

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