← View Generic P0812 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2021 Honda PASSPORT

P0812: P0812: Transmission Control Module (TCM) Internal Fault

on 2021 Honda PASSPORT

Fix Cost
$200 - $1000
Parts & Labor
Difficulty
3/5
1-2 hours
DIY Possible?
❌ No
Pro recommended
Your Vehicle
2021 Honda
PASSPORT
⚠️

Important for 2021 Honda PASSPORT Owners

Before starting repairs, verify which engine your 2021 Honda PASSPORT has. Check your VIN or engine code to ensure you order the correct parts.

📖 What Does P0812 Mean on 2021 Honda PASSPORT?

The Transmission Control Module (TCM) has detected an internal fault, which may be related to a faulty sensor, actuator, or internal circuit.
⚠️

Symptoms

  • • Transmission slipping
  • • hesitation
  • • or refusal to engage gears
  • • unusual noises
  • • or illumination of the Check Engine Light.
🔍

Common Causes

  • • Faulty transmission solenoid
  • • faulty transmission pressure sensor
  • • faulty transmission temperature sensor
  • • internal transmission circuit failure.
🛠️

How to Fix P0812 on 2021 Honda PASSPORT

1. Clear the code and monitor the vehicle to see if the code returns. If it does, replace the faulty component. 2. Use a scan tool to monitor transmission data to identify the faulty component. 3. Perform a transmission fluid flush and replace the fluid to ensure proper transmission operation.

🔧

Need Maintenance Info for Your PASSPORT?

Get oil capacity, filter specs, and torque settings for your specific 2021 Honda PASSPORT.

View 2021 Honda PASSPORT Specs

Parts for 2021 Honda PASSPORT

Transmission solenoid Shop ↗ Transmission pressure sensor Shop ↗ Transmission temperature sensor Shop ↗

Essential Tool

Must Have

OBD2 Scanner

Read & clear codes on your 2021 Honda PASSPORT

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🔗

Related Diagnostic Codes

Other codes that may appear with P0812

P0810 Sequential Code

P0810: Transmission Control Module (TCM) Range/Performance Problem

Medium
P0811 Sequential Code

P0811: Transmission Control Module (TCM) Range/Performance Issue

Medium
P0813 Sequential Code

P0813: Transmission Control Module (TCM) Internal Fault

Medium
P0814 Sequential Code

P0814: Transmission Control Module (TCM) Range/Performance Issue

Medium

💡 Why These Codes Are Related:

  • • Similar Issues: Same root cause or component failure
  • • Related Problems: Often occur together due to system interactions
  • • Sequential Codes: Progressive failure stages or multiple sensors
  • • Same System: Components within the same automotive system