If some DTCs are displayed at the same time, perform inspections one by one based on the following priority chart.

NOTE:

If DTC U1000 or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000, U1001. Refer to "DTC U1000, U1001 CAN COMMUNICATION LINE ".
If DTC U1010 is displayed with other DTC, first perform the trouble diagnosis for DTC U1010. Refer to "DTC U1010 CAN COMMUNICATION ".

DTC INSPECTION PRIORITY CHART

Priority	Detected items (DTC)
1	U1000 U1001 CAN communication line U1010 CAN communication P0101 P0102 P0103 Mass air flow sensor P0112 P0113 P0127 Intake air temperature sensor P0117 P0118 P0125 Engine coolant temperature sensor P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor P0128 Thermostat function P0181 P0182 P0183 Fuel tank temperature sensor P0327 P0328 Knock sensor P0335 Crankshaft position sensor (POS) P0340 Camshaft position sensor (PHASE) P0460 P0461 P0462 P0463 Fuel level sensor P0500 Vehicle speed sensor P0605 ECM P0643 Sensor power supply P0705 P0850 Park/Neutral position (PNP) switch P1610 - P1615 NATS P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
2	P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater P0075 Intake valve timing control solenoid valve P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1 P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2 P0441 EVAP control system purge flow monitoring P0443 P0444 P0445 EVAP canister purge volume control solenoid valve P0447 P0448 EVAP canister vent control valve P0451 P0452 P0453 EVAP control system pressure sensor P0603 ECM power supply P0710 P0715 P0720 P0740 P0744 P0745 P0746 P0776 P0778 P0840 P0845 P1740 CVT related sensors, solenoid valves and switches P1217 Engine over temperature (OVERHEAT) P1777 P1778 CVT step motor P1805 Brake switch P2100 P2103 Throttle control motor relay P2101 Electric throttle control function P2118 Throttle control motor
3	P0011 Intake valve timing control P0171 P0172 P0174 P0175 Fuel injection system function P0300 - P0304 Misfire P0420 P0430 Three way catalyst function P0442 P0456 EVAP control system (SMALL LEAK, VERY SMALL LEAK) P0455 EVAP control system (GROSS LEAK) P0506 P0507 Idle speed control system P1148 P1168 Closed loop control P1421 Cold start control P1564 ASCD steering switch P1572 ASCD brake switch P1574 ASCD vehicle speed sensor P1715 Primary speed sensor P2119 Electric throttle control actuator

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

DTC Inspection Priority Chart: Notes

Use the Manual With the Right Hardware

When to See a Mechanic