P1873 – OBD-II DTC

OBD-II DTC P1873 – Transmission Automatic 4-Wheel Drive Indicator (Lamp) Circuit Failure

DTC P1873 meaning

DTC P1873 refers to a fault in the automatic transmission’s 4-wheel drive indicator circuit. This code indicates that there is a malfunction in the circuit that controls the 4-wheel drive indicator lamp on the dashboard. The issue may stem from a variety of electrical or mechanical failures within the transmission system.

DTC P1873 symptoms

Common symptoms associated with DTC P1873 may include:

• Illumination of the 4-wheel drive indicator lamp
• Transmission shifting issues
• Inability to engage or disengage 4-wheel drive
• Erratic behavior of the transmission
• Potential loss of power to the wheels

DTC P1873 causes

Several factors can lead to the triggering of DTC P1873, including:

• Faulty 4-wheel drive indicator lamp
• Wiring issues such as shorts or open circuits
• Defective transmission control module (TCM)
• Malfunctioning transmission range sensor
• Corroded or loose connectors in the circuit

DTC P1873 seriousness

The seriousness of DTC P1873 can vary. While it may not cause immediate safety concerns, it can lead to:

• Reduced vehicle performance
• Inability to utilize 4-wheel drive when needed
• Potential further damage to the transmission system if left unaddressed

It is advisable to diagnose and repair the issue promptly to avoid complications.

How to diagnose DTC P1873

To diagnose DTC P1873, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1873 code.
2. Inspect the 4-wheel drive indicator lamp for functionality.
3. Check the wiring and connectors for any signs of damage or corrosion.
4. Test the transmission control module (TCM) for proper operation.
5. Examine the transmission range sensor for faults.
6. Clear the code and perform a road test to see if the code reappears.

How to fix DTC P1873 step-by-step instructions

To fix DTC P1873, follow these steps:

1. Inspect and repair any damaged wiring or connectors related to the 4-wheel drive indicator circuit.
2. Replace the faulty 4-wheel drive indicator lamp if it is not functioning.
3. Test and, if necessary, replace the transmission control module (TCM).
4. Check and replace the transmission range sensor if it is defective.
5. Clear the DTC using an OBD-II scanner after repairs are made.
6. Perform a road test to ensure the issue is resolved and the code does not return.

How to erase DTC P1873

To erase DTC P1873, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “On” position without starting the engine.
3. Access the scanner’s menu and select the option to clear or erase trouble codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and start the vehicle to ensure the code does not reappear.

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