AutoFaultCodes.com
OBD-II fault code definitions, symptoms, causes, and step-by-step diagnostics.
Vehicle contextNot a failure-frequency claim

Toyota Highlander OBD-II diagnostics

Toyota Highlander spans different model years, engines, transmissions, calibrations, and sometimes hybrid/electrified systems. An accurate diagnosis starts with the exact vehicle configuration and full scan-tool data—not the model name alone.

Accuracy note: this page does not label generic codes as “common Toyota Highlander failures” without vehicle-specific evidence. Use it as a navigation and diagnostic-context tool, not as a failure-rate list.

Before diagnosing a code

  • Record model year, VIN, engine, transmission, mileage, and recent repair history.
  • Run a full module scan and save freeze-frame/environmental data.
  • Note whether the MIL is steady or flashing and whether the fault is current, pending, history, or permanent.
  • For P1xxx codes, use Toyota-specific service information; the numeric code is not universal.
  • Check vehicle-specific TSBs/software updates only after confirming the exact applicability.

Verified generic starting points

These are useful generic reference pages, not claims that these codes occur more often on this model.

P0101
Mass or Volume Air Flow Sensor A Circuit Range/Performance
Open diagnostic workflow
P0128
Coolant Thermostat — Coolant Temperature Below Thermostat Regulating Temperature
Open diagnostic workflow
P0171
System Too Lean — Bank 1
Open diagnostic workflow
P0300
Random/Multiple Cylinder Misfire Detected
Open diagnostic workflow
P0420
Catalyst System Efficiency Below Threshold — Bank 1
Open diagnostic workflow
P0456
Evaporative Emission Control System Leak Detected — Very Small Leak
Open diagnostic workflow
P0016
Crankshaft Position–Camshaft Position Correlation — Bank 1 Sensor A
Open diagnostic workflow
P0562
System Voltage Low
Open diagnostic workflow
P0700
Transmission Control System — Malfunction Indicator Lamp Request
Open diagnostic workflow

When diagnosis should stop and become a repair-facility job

Use professional service when testing involves high-voltage hybrid/EV systems, high-pressure fuel systems, internal transmission work, airbag/SRS systems, programming/security functions, or when a flashing MIL, oil-pressure warning, severe overheating, fuel leak, or major mechanical noise is present.