Mode $06

📖 YOUCANIC Automotive Glossary

Mode $06 (On-Board Monitoring Test Results for Specific Monitored Systems) is an advanced OBD2 diagnostic mode that displays the actual measured test values for each diagnostic monitor alongside the pass/fail threshold limits — giving you the raw numbers behind each monitor’s pass or fail determination. While Mode $03 simply tells you a DTC was set (the test failed), Mode $06 shows you how close the system is to the pass/fail boundary. For example, the catalyst efficiency monitor might show an actual measured value of 0.75 with a maximum threshold of 0.85 — the system passes but is close to the limit, indicating the catalyst is aging.

Mode $06 data is invaluable for predicting developing problems before they trigger DTCs. A component whose Mode $06 values are trending toward the threshold is likely to fail soon even though it currently passes. This makes Mode $06 essential for pre-purchase inspections (is the catalytic converter marginal?), for verifying repairs actually improved the measured values (not just cleared the code), and for diagnosing intermittent codes that set and clear. The YOUCANIC UCAN-II displays Mode $06 test results with clear descriptions of each test ID, the measured value, minimum/maximum limits, and pass/fail status.