EG–534 ENGINE – 2JZ–GTE ENGINE TROUBLESHOOTING DTC 25 26 Air–Fuel Ratio Lean Rich Malfunction CIRCUIT DESCRIPTION See EG–525 for the circuit description. DTC No. | Diagnostic Trouble Code Detecting Condition | Trouble Area 25 (1) Main heated oxygen sensor voltage is 0.45 V or less (lean) for 90 sec. under conditions (a) and (b): (2 trip detection logic)*2 (a) Engine coolant temp.: 70°C (158°F) or more (b) Engine speed: 1,500 rpm or more • Open or short in main heated oxygen sensor circuit • Main heated oxygen sensor • Ignition system • ECM (2) Engine speed varies by more than 20 rpm over the preceding crank angle period during a period of 25 sec. or more under conditions (a) and (b): (2 trip detection logic).* (a) Engine speed: Below 950 rpm (b) Engine coolant temp.: 80°C (176°F) or more • Open and short in injector circuit • Fuel line pressure (injector leak, blockage) • Mechanical system malfunction (skipping teeth of timing belt) • Ignition system • Compression pressure (foreign object caught in valve) • Mass air flow meter (air intake) • ECM 26 Engine speed varies by more than 20 rpm over The preceding crank angle period during a Period of 25 sec. or more under conditions (a) And (b): (2 trip detection logic).* (a) Engine speed: Below 950 rpm (b) Engine coolant temp.: 80°C (176°F) or more • Open and short in injector circuit • Fuel line pressure (injector leak, blockage) • Mechanical system malfunction (skipping teeth of timing belt) • Ignition system • Compression pressure (foreign object caught in valve) • Mass air flow meter (air intake) • ECM *: See page EG–503.