Fix P0801: STEP-BY-STEP diagnostic GUIDE!

The P0801: Reverse Inhibit Control Circuit Malfunction refers to an issue where the reverse inhibit control circuit, which prevents reverse gear engagement under certain conditions (e.g., high speeds), is malfunctioning. This can be caused by a faulty circuit, wiring or connector issues, or a malfunctioning transmission control module (TCM).

P0801 – Quick Overview

CodeInformation
MeaningP0801: Reverse Inhibit Control Circuit Malfunction
Is it serious?Yes, if the reverse inhibit control circuit is malfunctioning, it could lead to improper engagement of reverse gear, causing potential drivability issues or safety risks.
Possible causes– Faulty reverse inhibit control circuit
– Wiring or connector issues
– Faulty transmission control module (TCM)
How to diagnose?– Test reverse inhibit control circuit
– Inspect wiring and connectors
– Replace faulty components if needed

P0801 Meaning

The P0801 code indicates a malfunction in the reverse inhibit control circuit, which is designed to prevent reverse gear from being engaged at inappropriate times, such as when the vehicle is moving forward at a high speed. If this circuit fails, it could lead to unsafe conditions or transmission damage.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for additional transmission-related codes that may help provide further insight into the issue.OBD-II Scanner
Test Reverse Inhibit Control CircuitUse a multimeter or diagnostic scanner to test the reverse inhibit control circuit for continuity and proper function. Compare readings against manufacturer specifications.Multimeter, Diagnostic Scanner
Inspect Wiring and ConnectorsInspect the wiring and connectors leading to the reverse inhibit control circuit for signs of damage, corrosion, or loose connections that could cause the malfunction.Flashlight, Multimeter, Safety Gloves
Check Transmission FluidEnsure that the transmission fluid level is correct and that the fluid is clean, as contaminated or low fluid can impact transmission performance.Transmission Fluid Tester, Dipstick
Test Transmission Control Module (TCM)If no issues are found in the circuit or wiring, test the TCM to check for faults or communication issues that may be affecting the reverse inhibit function.Diagnostic Scanner, TCM Testing Tools
Replace Faulty ComponentsIf the reverse inhibit control circuit, TCM, or any associated wiring is found to be faulty, replace the defective parts according to manufacturer specifications.Replacement Parts, Wrenches, Screwdrivers
Clear the Code and Test DriveAfter replacing or repairing the components, clear the code using an OBD-II scanner and test drive the vehicle to confirm the issue is resolved.OBD-II Scanner
Recheck for CodesAfter the test drive, rescan the vehicle to ensure the P0801 code has not returned.OBD-II Scanner
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