P0212 medium Severity

P0212: Injector Circuit Malfunction - Cylinder 12

May cause rough idle, misfire, loss of power and increased fuel consumption; not recommended to continue driving long‑term with code present

Overview

P0212 is an OBD‑II generic powertrain trouble code indicating an injector circuit malfunction for cylinder 12, typically due to electrical issues in the injector circuit or a faulty injector leading to misfire and performance issues.

Common Symptoms

  • Check Engine Light illuminated
  • Rough idle
  • Engine misfire on cylinder 12
  • Reduced engine performance
  • Increased fuel consumption

Most Common Causes

Faulty or failed fuel injector for cylinder 12 high

Injector itself often fails or has internal short/open, leading PCM to detect improper voltage/ resistance.

Open or short in injector wiring harness or connector high

Damaged, corroded or disconnected wiring/connector commonly interrupts signal or supply to injector.

PCM/ECM driver circuit failure medium

Rare but possible; PCM output driver for injector circuit may be damaged and fail to provide correct pulse signal.

Poor power supply or ground for injector circuit medium

Weak ground or supply (fuse, battery connection) can cause voltage sag and trigger the code.

Diagnostic Steps

  1. Scan vehicle with OBD‑II scanner to confirm P0212 and check for related codes
    Expected: Code P0212 present; possibly other injector or misfire codes
    Interpretation: Confirms fault in cylinder 12 injector circuit and identifies any concurrent faults.
  2. Visually inspect wiring and connector for cylinder 12 injector
    Expected: No broken, corroded, or loose wires/connectors
    Interpretation: Visible damage suggests wiring/connector issue; repair/replace as needed.
  3. Measure injector resistance with multimeter
    Expected: Resistance within OEM spec for injector
    Interpretation: Out‑of‑spec reading indicates faulty injector requiring replacement.
  4. Check voltage and ground at injector with ignition on and engine cranking
    Expected: Proper voltage supply and solid ground signal
    Interpretation: Absence of supply/ground indicates power/ground or PCM output issue.
  5. Perform continuity test from PCM to injector connector
    Expected: Continuity with low resistance
    Interpretation: Open circuit indicates wiring fault; diagnose and repair harness.

Repair Solutions

Repair or replace damaged wiring or connectors to injector medium
Estimated Cost: $80 - $250

Wiring harness repair often resolves open/short faults; cost depends on extent of damage.

Replace faulty fuel injector for cylinder 12 medium
Estimated Cost: $150 - $400

Injector cost varies by vehicle; includes part and labor.

Repair or replace PCM/ECM if output driver is confirmed faulty hard
Estimated Cost: $600 - $1200

PCM replacement and programming is costly; only after all other diagnostics confirm PCM fault.

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Assuming PCM failure before thoroughly testing injector and wiring
  • Replacing injector without checking wiring and connectors
  • Ignoring power supply or ground issues in the circuit

Frequently Asked Questions

Technical definition of P0212 OBD-II Code

When your OBD-II scanner reads P0212, it means: Injector Circuit Malfunction - Cylinder 12. This code is related to the vehicle's Fuel System.

Should I stop driving if I have P0212?

You should treat P0212 as a medium issue. May cause rough idle, misfire, loss of power and increased fuel consumption; not recommended to continue driving long‑term with code present

Common signs of the P0212 error code

You may experience the following: Check Engine Light illuminated, Rough idle, Engine misfire on cylinder 12.

Common triggers for the P0212 error

The most common causes are: Faulty or failed fuel injector for cylinder 12, Open or short in injector wiring harness or connector, PCM/ECM driver circuit failure.

Estimated repair costs for different causes of P0212

Expect to pay around $250 if the issue is a Repair or replace damaged wiring or connectors to injector, but up to $1200 if the Repair or replace PCM/ECM if output driver is confirmed faulty needs replacement.

Is the P0212 code specific to Toyota?

This is a universal code. You might see P0212 on Ford, Chevrolet, Toyota, Honda, Nissan, or any other OBD-II vehicle.

User Comments (0)

Share your experience or ask a question about this code.

Be the first to share your experience with P0212!