P0812 — Reverse Input Circuit

What Does P0812 Mean?

P0812 is a diagnostic trouble code indicating: Reverse Input Circuit. This code relates to the transmission system. It has been reported in NHTSA complaints across 1 different vehicle models.

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"I WENT TO A MECHANIC TODAY, I HAVE 'PASSENGER AIRBAG OFF LIGHT FLASHING' HE TOLD ME HONDAS HAVE RECALLED FOR AIRBAGS IN DEALERSHIPS SO I CHECKED MY VEHICLE REPORT IT SAYS THAT I HAD 2 RECALLS IN 2019 AND I DID THEM BUT I DIDN'T. 'RECALL SUBJECT: AIR BAGS: PASSENGER SIDE FRONTAL REPORT RECEIPT DATE:"
— Honda Civic owner, 12/29/2018

Source: NHTSA Complaints Database

Most Reported Vehicles for P0812

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	HONDA CIVIC

Frequently Asked Questions

Is it safe to drive with this transmission code?

Use caution. Transmission codes can indicate serious issues that worsen with continued driving. Avoid highway speeds until diagnosed.

Do I need a full transmission rebuild?

Not necessarily. Many transmission codes are caused by solenoids, sensors, or low fluid — which are much cheaper fixes than a rebuild.

How much does a transmission repair cost?

Solenoid replacement: $200-500. Valve body: $500-1,000. Full rebuild: $1,800-3,500. Get a proper diagnosis first.

What To Do Next

Possible Fixes

🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
🔧 Check transmission fluid level and condition; top off or change if needed
🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P0812: Reverse Input Circuit