P0804 – OBD-II DTC

OBD-II DTC P0804 – Shift/Timing Solenoid Intermittent

DTC P0804 meaning

DTC P0804 refers to a diagnostic trouble code indicating an issue with the shift or timing solenoid in an automatic transmission. This code is triggered when the Engine Control Module (ECM) detects an intermittent fault in the solenoid’s operation, which can affect the transmission’s ability to shift gears properly.

DTC P0804 symptoms

Common symptoms associated with DTC P0804 may include:

• Harsh or erratic shifting of the transmission
• Delayed engagement when shifting from park to drive or reverse
• Transmission slipping or failing to shift
• Check Engine Light illuminated on the dashboard
• Unusual noises from the transmission

DTC P0804 causes

Several factors can lead to the triggering of DTC P0804, including:

• Faulty shift solenoid or timing solenoid
• Wiring issues, such as damaged or corroded connectors
• Low transmission fluid levels or contaminated fluid
• Faulty transmission control module (TCM)
• Mechanical issues within the transmission

DTC P0804 seriousness

DTC P0804 can be considered a moderate to serious issue. If left unaddressed, it may lead to further transmission damage, reduced vehicle performance, and potential safety hazards due to unpredictable shifting behavior. It is advisable to diagnose and repair the issue promptly to avoid more extensive repairs.

How to diagnose DTC P0804

To diagnose DTC P0804, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P0804 code.
2. Check for any additional trouble codes that may provide more context.
3. Inspect the wiring and connectors related to the shift solenoid for damage or corrosion.
4. Check the transmission fluid level and condition.
5. Test the shift solenoid operation using a multimeter or by applying direct power to it.
6. Examine the transmission control module for faults.
7. Perform a road test to observe the transmission behavior.

How to fix DTC P0804 step-by-step instructions

To fix DTC P0804, follow these steps:

1. Address any wiring or connector issues found during diagnosis.
2. If the shift solenoid is faulty, replace it with a new one.
3. Change the transmission fluid if it is low or contaminated.
4. Repair or replace the transmission control module if necessary.
5. Clear the DTC using an OBD-II scanner.
6. Perform a road test to ensure the issue is resolved and the code does not return.

How to erase DTC P0804

To erase DTC P0804, 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 trouble codes menu on the scanner.
4. Select the option to clear or erase codes.
5. Confirm the action and wait for the scanner to complete the process.
6. Disconnect the scanner and start the vehicle to check if the code reappears.

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