P0801 moderate

Reverse Inhibit Control Circuit Malfunction

The P0801 code means the vehicle's onboard diagnostic system has detected: Reverse Inhibit Control Circuit Malfunction. This is a moderate severity code.

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Keep driving?: Short distances only
DIY difficulty: hard
Estimated cost: $200 - $900 (parts and labor)

Check Your Fluid First

ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

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Read Transmission Codes

LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

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Common Symptoms

Check Engine Light illuminated
Vehicle may not shift into reverse properly
Transmission warning light on
Harsh engagement when selecting reverse

Probable Causes (Ranked by Likelihood)

Faulty reverse inhibit solenoid Very High
Wiring or connector issue in reverse inhibit circuit High
Transmission control module (TCM) malfunction Moderate
Mechanical failure in transmission valve body Low

Step-by-Step Diagnostic Procedure

Scan for additional transmission codes and check freeze frame data
Inspect wiring and connector at the reverse inhibit solenoid
Test reverse inhibit solenoid resistance and compare to specifications
Check TCM outputs using a bidirectional scan tool

Frequently Asked Questions

What does the reverse inhibit control do?

The reverse inhibit system prevents the transmission from engaging reverse at high speeds, protecting the transmission from damage.

Can a bad reverse inhibit solenoid damage my transmission?

If left unrepaired, it can lead to harsh engagement or unintended gear engagement, which may cause internal transmission damage over time.

Is this code common?

P0801 is relatively uncommon and typically appears on vehicles with electronically controlled transfer cases or advanced transmission control systems.