C1860 – OBD-II DTC

OBD-II DTC C1860 – PRNDL Input #3 Circuit Failure

DTC C1860 meaning

DTC C1860 refers to a fault in the PRNDL (Park, Reverse, Neutral, Drive, Low) input #3 circuit. This code indicates that the vehicle’s powertrain control module (PCM) has detected an issue with the signal from the PRNDL switch, which is responsible for indicating the current gear selection to the PCM. A failure in this circuit can lead to improper gear shifting and affect the overall performance of the vehicle.

DTC C1860 symptoms

Common symptoms associated with DTC C1860 may include:

• Illumination of the check engine light
• Erratic or incorrect gear shifting
• Transmission may not engage or may slip
• Vehicle may enter limp mode
• Inability to shift into certain gears

DTC C1860 causes

Several factors can lead to the occurrence of DTC C1860, including:

• Faulty PRNDL switch
• Wiring issues, such as shorts or open circuits in the PRNDL input #3 circuit
• Corroded or loose connectors
• Faulty PCM or software issues
• Electrical interference from other components

DTC C1860 seriousness

DTC C1860 can be considered serious as it directly affects the transmission’s ability to function correctly. If left unaddressed, it may lead to:

• Increased wear and tear on the transmission
• Potential for complete transmission failure
• Safety risks due to unexpected gear changes
• Inability to drive the vehicle properly

How to diagnose DTC C1860

To diagnose DTC C1860, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC.
2. Inspect the PRNDL switch for any visible damage or wear.
3. Check the wiring and connectors associated with the PRNDL input #3 circuit for shorts, opens, or corrosion.
4. Test the PRNDL switch using a multimeter to ensure it is functioning correctly.
5. Examine the PCM for any software updates or faults.
6. Clear the DTC and perform a road test to see if the code reappears.

How to fix DTC C1860 step-by-step instructions

To fix DTC C1860, follow these steps:

1. Inspect and repair any damaged wiring or connectors in the PRNDL input #3 circuit.
2. Replace the PRNDL switch if it is found to be faulty.
3. Ensure all connections are clean and secure to prevent electrical interference.
4. Update the PCM software if necessary, following manufacturer guidelines.
5. Clear the DTC using an OBD-II scanner.
6. Perform a road test to confirm that the issue has been resolved and the DTC does not return.

How to erase DTC C1860

To erase DTC C1860, you can 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. Access the DTC menu on the scanner and locate DTC C1860.
4. Select the option to clear or erase the DTC.
5. Turn off the ignition and disconnect the scanner.
6. Start the vehicle and monitor for any reoccurrence of the DTC.

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