11 Crank angle sensor/circuit (1988 to 1990); Crankshaft position sensor (1991 to 1996) 12 Air flow Meter/circuit open or shorted 13 Cylinder head temperature sensor(Maxima and 300ZX models); all others coolant temperature sensor circuit 14 Vehicle Speed Sensor signal circuit is open 15 Mixture ratio is too lean despite feedback control; fuel injector clogged 21 Ignition signal in the primary circuit is not being entered to the ECU during cranking or tuning 22 Fuel pump circuit (Maxima and 1987 and later 300ZX models); all others idle speed control valve or circuit 23 Idle switch (throttle valve switch) signal circuit open 24 Park/netural switch malfunctioning 25 Idle speed control valve circuit is open or shorted 26 Turbo boost 28 Cooling fan 29 Fuel system rich 31 1984 through 1986 EFI models; Problem in air conditioning system; all other models: ECU internal problem 32 1984 through 1986 EFI models; check starter system. All other models: EGR malfuntion (California models) 33 Oxygen sensor or circuit (300ZX left side) - all other models EGR malfunction 34 Detonation (Knock) sensor 35 Exhaust gas temperature sensor (California models) 36 EGR transducer 37 Closed loop control/front oxygen sensor (Maxima) 41 Maxima and 1984 through 1987 300ZX models; fuel temp sensor circuit. All other models: air temperature sensor circuit 42 1988 and later 300ZX models; fuel temperature sensor circuit; all other models: throttle sensor circuit 43 The mixture ratio is too lean despite feedback control; fuel injector clogged (1987 Sentra only): All others; Throttle position sensor circuit is open or shorted 44 No trouble codes stored in ECU 45 Injector fuel leak (California models only) 51 Fuel injector circuit open (California models only) 53 Oxygen sensor (300ZX right side) 54 Short between automatic transmission control unit(TCU) and ECU 55 Normal engine management system operation is indicated 63 Misfire detected - cylinder no. 6 64 Misfire detected - cylinder no. 5 65 Misfire detected - cylinder no. 4 66 Misfire detected - cylinder no. 3 67 Misfire detected - cylinder no. 2 68 Misfire detected - cylinder no. 1 71 Misfire detected - random 72 Catalytic converter malfunction (right side) 74 EVAP pressure sensor 75 EVAP leak 76 Fuel injection system 77 Rear oxygen sensor 81 Vacuum cut bypass valve 82 Crankshaft sensor 84 Automatic trans-to-fuel injection communication 85 VTC solenoid 87 EVAP canister purge control 91 Front oxygen sensor 95 Crankshaft sensor 98 Coolant temperature sensor 101 Camshaft sensor 103 Park/neutral switch 105 EGR and canister control valve 108 EVAP volume control