The P0801 trouble code indicates a malfunction in the reverse inhibit control circuit.
P0801 Reverse Inhibit Control Circuit Malfunction
Code symptoms P0801.
1. The Check Engine Light (CEL) or Malfunction Indicator Lamp (MIL) will likely illuminate on the dashboard.
2. Difficulty engaging or disengaging the vehicle’s reverse gear.
3. The vehicle may not shift into reverse at all.
4. Other transmission-related issues may be present, such as harsh shifting or slipping.
Causes of the code P0801.
1. Faulty reverse inhibit solenoid.
2. Wiring issues, such as damaged or corroded connectors, broken wires, or short circuits in the reverse inhibit circuit.
3. Issues with the transmission control module (TCM).
4. Mechanical problems within the transmission, such as a faulty valve body or clutch.
Code Solutions P0801.
1. Use an OBD-II scanner to retrieve freeze frame data and any other stored trouble codes. This information can provide insight into when and how the malfunction occurred.
2. Perform a visual inspection of the reverse inhibit solenoid and its wiring harness. Look for any signs of damage, corrosion, or loose connections. Repair or replace any damaged components as needed.
3. Use a multimeter to test the reverse inhibit solenoid for proper operation. If the solenoid does not actuate when commanded by the TCM, it may be faulty and require replacement.
4. Check the transmission fluid level and condition. Low or contaminated transmission fluid can affect transmission operation, including the ability to engage reverse gear. If the fluid is low, top it up to the appropriate level. If it’s contaminated or burnt, a fluid flush and replacement may be necessary.
5. If the solenoid and wiring check out okay, perform a diagnostic scan of the TCM to check for any stored trouble codes or pending codes that may provide additional information about the issue.
6. Conduct a thorough inspection of the transmission for any mechanical issues, such as a faulty valve body or clutch. Repair or replace any damaged components as needed.
7. Clear the trouble codes from the vehicle’s computer memory and test drive the vehicle to see if the code returns. If it does, further diagnosis or repairs may be required.