| Flash code | OBD·II code | Fault location | Probable cause |
| – | PO, P2, uo | Refer to OBD-11 trouble code tables | – |
| 1 | – | Heated oxygen sensor (H02S)- front – circuit/voltage low/high | Wiring open/short circuit, H02S, fuel system, ECM |
| 3 | – | Manifold absolute pressure (MAP) sensor – circuit/voltage high/low | Wiring, MAP sensor, ECM |
| 4 | – | Crankshaft position (CKP) sensor- circuit malfunction/range/performance problem | Wiring, CKP sensor, valve timing, ECM |
| 5 | – | Manifold absolute pressure (MAP) sensor – range/performance problem | Hose leak, MAP sensor |
| 5 | P1128 | Manifold absolute pressure (MAP) sensor – pressure lower than expected | MAP sensor |
| 5 | P1129 | Manifold absolute pressure (MAP) sensor – pressure higher than expected | MAP sensor |
| 6 | – | Engine coolant temperature (ECT) sensor- circuit/voltage low/high | Wiring short/open circuit, ECT sensor, ECM |
| 7 | – | Throttle position (TP) sensor- circuit/
voltage low/high | Wiring, TP sensor, ECM |
| 7 | P1121 | Throttle position (TP) sensor- position lower than expected | TP sensor |
| 7 | P1122 | Throttle position (TP) sensor – position higher than expected | TP sensor |
| 8 | P1359 | Crankshaft position (CKP) sensor – connector disconnection | Wiring |
| 8 | P1361 | Crankshaft position (CKP) sensor- intermittent signal | CKP sensor |
| 8 | P1362 | Crankshaft position (CKP) sensor- no signal | Wiring, CKP sensor, ECM |
| 9 | P1381 | Camshaft position (CMP) sensor – intermittent signal | CMP sensor |
| 9 | P1382 | Camshaft position (CMP) sensor- no signal | Wiring, CMP sensor, ECM |
| 10 | – | Intake air temperature (IAT) sensor- circuit/voltage low/high
| Wiring short/open circuit, IAT sensor, ECM |
| 12 | P1491 | Exhaust gas recirculation (EGR) system – valve lift insufficient | Wiring, EGR valve/position sensor, EGR
solenoid, hose leak/blockage, ECM |
| 12 | P1498 | Exhaust gas recirculation (EGR) valve position sensor – voltage high | Wiring, EGR valve/position sensor, ECM |
| 13 | P1106 | Barometric pressure (BARO) sensor- range/performance problem | ECM |
| 13 | P1107 | Barometric pressure (BARO) sensor- circuit/voltage low | ECM |
| 13 | P1108 | Barometric pressure (BARO) sensor- circuit/voltage high | ECM |
| 14 | – | Idle control system – malfunction | lAC valve, fast idle thermo valve, throttle body |
| 14 | P1508 | Idle air control (lAC) valve – circuit failure | Wiring, lAC valve, ECM |
| 14 | P1519 | Idle air control (lAC) valve – circuit failure | Wiring, lAC valve, ECM |
| 17 | – | Vehicle speed sensor (VSS) – circuit malfunction/range/performance problem | Wiring, VSS, ECM |
| 20 | P1297 | Electrical load sensor – circuit/voltage low | Wiring, electrical load sensor, ECM |
| 20 | P1298 | Electrical load sensor – circuit/voltage high | Wiring, electrical load sensor, ECM |
| 21 | P1253 | VTEC system – malfunction | Wiring, VTEC solenoid, ECM |
| 22 | P1259 | VTEC system – malfunction | Wiring, VTEC solenoid/pressure switch, ECM |
| 23 | – | Knock sensor (KS) – circuit malfunction | Wiring, KS, ECM |
| 30 | P1681 | AT to ECM- signal A- voltage low | Wiring, TCM, ECM |
| 30 | P1682 | AT to ECM- signal A- voltage high | Wiring, TCM, ECM |
| 31 | P1686 | AT to ECM- signal B- voltage low | Wiring, TCM, ECM |
| 31 | P1687 | AT to ECM- signal 8- voltage high | Wiring, TCM, ECM |
| 41 | – | Heated oxygen sensor (H02S) – front – circuit malfunction | Wiring, ECM |
| 45 | – | Mixture too lean/rich | Fuel system, front H025, injectors, MAP
sensor, wiring, mechanical fault |
| 61 | – | Heated oxygen sensor (H02S) – front – slow response | H02S, exhaust system |
| 63 | – | Heated oxygen sensor (H02S)- rear- slow response/circuiUvoltage low/high | Wiring, H02S, ECM |
| 65 | – | Heated oxygen sensor (H02S) – rear – circuit malfunction | Wiring, ECM |
| 67 | – | Catalytic converter – efficiency below limit | Catalytic converter, rear H02S |
| 70 | – | AT – lock-up clutch not engaging/no gear shitupoor gear shift | Wiring, mainshaft speed sensor, countershaft speed sensor, lock-up control system, shift solenoid (SS) A/8/C, ECM, TCM |
| 70 | P1660 | AT to ECM – data line failure – V6 | Wiring, TCM, ECM |
| 70 | P1705 | AT – gear shift malfunction | Wiring, range position switch, ECM, TCM |
| 70 | P1705 | AT – lock-up clutch not engaging | Wiring, range position switch, ECM, TCM |
| 70 | P1706 | AT – gear shift malfunction | Wiring, range position switch, ECM, TCM |
| 70 | P1706 | AT- lock-up clutch malfunction | Wiring, range position switch, ECM, TCM |
| 70 | P1738 | Automatic transmission – except V6 | Wiring, clutch pressure switch 2, ECM |
| 70 | P1739 | Automatic transmission – except V6 | Wiring, clutch pressure switch 3, ECM |
| 70 | P1753 | AT – lock-up clutch not engaging/
disengaging | Wiring, lock-up control solenoid A, ECM, TCM |
| 70 | P1758 | AT – lock-up clutch not engaging | Wiring, lock-up control solenoid B, ECM, TCM |
| 70 | P1768 | AT- no gear shift- except V6 | Wiring, clutch pressure control solenoid
A, ECM |
| 70 | P1768 | AT- poor gear shift – V6 | Wiring, linear solenoid, TCM |
| 70 | P1768 | AT – lock-up clutch not engaging – V6 | Wiring, linear solenoid, TCM |
| 70 | P1773 | AT – no gear shift – except V6 | Clutch pressure control solenoid B, ECM |
| 70 | P1773 | AT – lock-up clutch not engaging – except V6 | Clutch pressure control solenoid B, ECM |
| 70 | P1786 | AT – poor gear shift – V6 | Communication wire, ECM |
| 70 | P1790 | AT- lock-up clutch not engaging- V6 | Wiring, TP sensor, TCM |
| 70 | P1791 | AT – lock-up clutch not engaging- V6 | Wiring, VSS, TCM |
| 70 | P1792 | AT – lock-up clutch not engaging – V6 | Wiring, ECT sensor, TCM |
| 70 | P1794 | Automatic transmission – BARO signal – V6 | Wiring, ECM, TCM |
| 71 | – | Cylinder No.1 – misfire | Fuel/ignition/EGR system, injector, wiring, mechanical fault |
| 72 | – | Cylinder No.2 – misfire | Fuellignition/EGR system, injector, wiring, mechanical fault |
| 73 | – | Cylinder No.3 – misfire | Fuel/ignition/EGR system, injector, wiring, mechanical fault |
| 74 | – | Cylinder No.4 – misfire | Fuel/ignition/EGR system, injector, wiring, mechanical fault |
| 75 | – | Cylinder No.5 – misfire | Fuellignition/EGR system, injector, wiring, mechanical fault |
| 76 | – | Cylinder No.6 – misfire | Fuel/ignition/EGR system, injector, wiring, mechanical fault |
| – | P1300 | Random misfire | lgnition/fuei/EGR system, MAP sensor, lAC valve |
| 80 | – | Exhaust gas recirculation (EGR) solenoid – insufficient flow | EGR valve, hose leak/blockage |
| 86 | – | Engine coolant temperature (ECT) sensor – range/performance problem | ECT sensor, cooling system |
| 90 | P1456 | Evaporative emission (EVAP) canister purge system (fuel tank system) – leak detected | Hose, fuel tank/pressure sensor, fuel filler cap, EVAP valve/bypass solenoid, EVAP two way valve, EVAP canister/vent valve |
| 90 | P1457 | Evaporative emission (EVAP) canister purge system (canister system)- leak detected | Hose, fuel tank/pressure sensor, EVAP valve/bypass solenoid, EVAP two way valve, EVAP canister/vent valve |
| 91 | – | Fuel tank pressure sensor- range/ performance problem/circuit/voltage low/ high | Hose leak/blockage, wiring, pressure sensor, ECM |
| 92 | – | Evaporative emission (EVAP) canister purge system – incorrect flow | Wiring, EVAP solenoid/flow switch, throttle body, hose leak/blockage, ECM |
| 92 | P1459 | Evaporative emission (EVAP) canister purge system – switch malfunction | Wiring, EVAP flow switch, hose leak/
blockage, ECM |
| – | P1607 | Engine control module (ECM) – internal circuit failure | ECM |