| Scan code | Fault location | Probable cause |
| PO, P2, UO | Refer to OBO-II trouble code tables | – |
| P1000 | System readiness test not complete | – |
| P1001 | Self Test | – |
| P1100 | Mass air flow (MAF) sensor – circuit intermittent | Wiring, MAF sensor |
| P1101 | Mass air flow (MAF) sensor – signal malfunction | Wiring, battery, MAF sensor, ECM |
| P1109 | Intake air temperature (IAT) sensor 2 – circuit
intermittent | Wiring, IAT sensor, ECM |
| P1112 | Intake air temperature (IAT) – circuit intermittent | Wiring, IAT sensor, ECM |
| P1114 | Intake air temperature (IAT) sensor 2 – low
input | Wiring short circuit to ground, IAT sensor, ECM |
| P1115 | Intake air temperature (IAT) sensor 2 – high
input | Wiring, IAT sensor, ECM |
| P1116 | Cylinder head temperature (CHT) sensor – out
of self-test range | Wiring, cooling system fault, CHT sensor |
| P1116 | Engine coolant temperature (ECT) sensor –
signal malfunction | Wiring, coolant thermostat, cooling system,
ECT sensor, ECM |
| P1117 | Cylinder head temperature (CHT) sensor – out
of self-test range | Wiring, cooling system fault, CHT sensor |
| P1117 | Engine coolant temperature (ECT) sensor –
circuit intermittent | Wiring, ECT sensor, cooling system, ECM |
| P1120 | Throttle position (TP) sensor – signal
malfunction, low | Wiring, TP sensor, ECM |
| P1121 | Throttle position (TP) sensor – inconsistent
with mass air flow (MAF) sensor signal | Wiring, MAF sensor, TP sensor, air leak |
| P1124 | Throttle position (TP) sensor -signal malfunction | Mechanical fault, TP sensor, ECM |
| P1125 | Throttle position (TP) sensor -circuit intermittent | Wiring, TP sensor |
| P1127 | Self test not completed -heated oxygen sensor(H02S), not tested | Engine not running long enough prior to self-test |
| P1128 | Heated oxygen sensor (H02S) 1, bank 1/bank 2 -interchanged | Wiring, connectors swapped |
| P1129 | Heated oxygen sensor (H02S) 2, bank 1/bank 2 -interchanged | Wiring, connectors swapped |
| P1130 | Heated oxygen sensor (H02S) 1, bank 1 -fueltrim (FT), at limit | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression, ECM |
| P1131 | Heated oxygen sensor (H02S) 1, bank 1 -not switching, fuel trim (FT) weak mixture | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression,ECM |
| P1132 | Heated oxygen sensor (H02S) 1, bank 1 -notswitching, fuel trim (FT) rich mixture | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression,ECM |
| P1137 | Heated oxygen sensor (H02S) 2, bank 1 -not switching, fuel trim (FT) weak mixture | Wiring, exhaust system leaking, H02S |
| P1138 | Heated oxygen sensor (H02S) 2, bank 1 -notswitching, fuel trim (FT) rich mixture | Wiring, exhaust system leaking, H02S |
| P1150 | Heated oxygen sensor (H02S) 1, bank 2 -fuel trim (FT), at limit | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression, ECM |
| P1151 | Heated oxygen sensor (H02S) 1, bank 2 -notswitching, fuel trim (FT) weak mixture | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression, ECM |
| P1152 | Heated oxygen sensor (H02S) 1, bank 2 -notswitching, fuel trim (FT) rich mixture | Wiring, intake/fuel system, H02S, EGR system, oil level, camshaft timing, cylinder compression, ECM |
| P1157 | Heated oxygen sensor (H02S) 2, bank 2 -notswitching, fuel trim (FT) weak mixture | Wiring, exhaust system leaking, H02S |
| P1158 | Heated oxygen sensor (H02S) 2, bank 2 -notswitching, fuel trim (FT) rich mixture | Wiring, exhaust system leaking, H02S |
| P1168 | Fuel rail pressure sensor -signal low | Wiring, fuel level, low fuel pressure, fuel rail pressure sensor |
| P1169 | Fuel rail pressure sensor -signal high | Wiring, high fuel pressure, fuel rail pressure sensor |
| P1180 | Fuel delivery system -pressure low | Fuel filter blocked, fuel supply blocked |
| P1181 | Fuel delivery system -pressure high | Fuel pressure regulator |
| P1183 | Engine oil temperature (EOT) sensor -circuit malfunction | Wiring, EOT sensor, ECM |
| P1184 | Engine oil temperature (EOT) sensor -out of self-test range | Wiring, EOT sensor, ECM |
| P1220 | Throttle control system (traction control) malfunction | Wiring, throttle position motor, mechanical fault, TP sensor, ECM |
| P1224 | Throttle position (TP) sensor (traction control), voltage out of range | Wiring, mechanical fault, TP sensor |
| P1229 | Supercharger (SC) intercooler pump | Wiring, SC intercooler pump, SC intercooler pump relay, ECM |
| P1230 | Fuel pump/variable load control module- circuit intermittent . | Wiring |
| P1231 | Fuel pump -circuit malfunction | Wiring, fuel pump relay |
| P1232 | Low speed fuel pump -malfunction | Wiring, low speed fuel pump relay, ECM |
| P1233 | Fuel system -malfunction | Wiring, IFS switch, fuel pump, fuel pump control module, ECM |
| P1234 | Fuel system -malfunction | Wiring, IFS switch, fuel pump, fuel pump control module, ECM |
| P1235 | Fuel pump control -signal malfunction | Wiring, fuel pump, fuel pump control module, ECM |
| P1236 | Fuel pump control -signal malfunction | Wiring, fuel pump, fuel pump control module, ECM |
| P1237 | Fuel pump -circuit malfunction | Wiring, fuel pump, fuel pump relay, fuel pump control module |
| P1238 | Fuel pump -circuit malfunction | Wiring, fuel pump, fuel pump relay, fuel pump control module |
| P1244 | Alternator -low input | Wiring, alternator, drive belt, ECM |
| P1245 | Alternator -high input | Wiring, alternator, ECM |
| P1246 | Alternator | Wiring, alternator, drive belt, ECM |
| P1260 | Theft detected -vehicle immobilized | – |
| P1270 | Maximum engine RPM or vehicle speed limit reached | Engine over revved in neutral, wheel slippage |
| P1285 | Cylinder head temperature (CHT) sensor overheat condition | Wiring, cooling system fault, CHT sensor |
| P1288 | Cylinder head temperature (CHT) sensor out of self-test range | Wiring, cooling system fault, CHT sensor |
| P1289 | Cylinder head temperature (CHT) sensor high input | Wiring, cooling system fault, CHT sensor |
| P1290 | Cylinder head temperature (CHT) sensor -low input | Wiring, cooling system fault, CHT sensor |
| P1299 | Cylinder head temperature (CHT) sensor over temperature condition | Wiring, cooling system fault, CHT sensor |
| P1309 | Misfire monitor disabled | CMP sensor, CKP sensor, ECT sensor, MAF sensor, ECM |
| P1351 | Ignition system diagnostic monitor -input circuit malfunction | Wiring, ECM |
| P1352 | Ignition coil 1, primary -circuit malfunction | Wiring, spark plug(s), ignition coil, ICM |
| P1353 | Ignition coil 2, primary -circuit malfunction | Wiring, spark plug(s), ignition coil, ICM |
| P1354 | Ignition coil 3, primary -circuit malfunction | Wiring, spark plug(s), ignition coil, ICM |
| P1355 | Ignition coil 4, primary -circuit malfunction | Wiring, spark plug(s), ignition coil, ICM |
| P1358 | Ignition system diagnostic monitor -out of self-test range | Wiring, ignition coil, ECM |
| P1359 | Ignition system -spark output (SPOUT) signal -circuit malfunction | Wiring, ECM |
| P1364 | Ignition coil, primary -circuit malfunction | Wiring, spark plug(s), ignition coil, ICM |
| P1380 | Camshaft position (CMP) actuator -circuit malfunction | Wiring, CMP actuator, ECM |
| P1381 | Camshaft position (CMP) actuator, bank 1 timing over advanced | Wiring, timing belt/chain, CMP actuator, low oil pressure |
| P1383 | Camshaft position (CMP) actuator, bank 1 timing over retarded | Wiring, timing belt/chain, CMP actuator |
| P1390 | Octane adjustment | Octane adjustment connector, ECM |
| P1400 D | Exhaust gas recirculation (EGR) valve position sensor low input | Wiring, EGR solenoid, EGR valve position sensor, ECM |
| P1400 a | Exhaust gas recirculation (EGR) pressure sensor circuit malfunction, low input | Wiring, EGR pressure sensor, ECM |
| P1401 D | Exhaust gas recirculation (EGR) valve position sensor high input | Wiring, EGR solenoid, EGR valve position sensor,ECM |
| P1401 a | Exhaust gas recirculation (EGR) pressure sensor circuit malfunction, high input | Wiring, EGR pressure sensor, ECM |
| P1403 | Exhaust gas recirculation (EGR) pressure sensor | Pressure hoses reversed |
| P1405 | Exhaust gas recirculation (EGR) system upstream hose off or plugged | EGR hoses |
| P1406 | Exhaust gas recirculation (EGR) system -downstream hose off or blocked | EGR hoses |
| P1407 | Exhaust gas recirculation (EGR) solenoid | Wiring, hose leak/blockage, EGR solenoid, EGR valve position sensor, ECM |
| P1408 | Exhaust gas recirculation (EGR) system out of self-test range | Wiring, EGR hoses, EGR valve, EGR solenoid,ECM |
| P1409 | Exhaust gas recirculation (EGR) solenoid -circuit malfunction | Wiring, EGR solenoid, ECM |
| P1411 | Secondary air injection (AIR) system malfunction | AIR hoses, AIR pump, AIR solenoid |
| P1413 | Secondary air injection monitor circuit -low input | Wiring, AIR solenoid, AIR pump, ECM |
| P1414 | Secondary air injection monitor circuit -high input | Wiring, AIR solenoid, ECM |
| P1442 | Evaporative emission (EVAP) system -small leak detected | Hose connection(s), intake leak, EVAP canister,EVAP canister purge valve |
| P1443 | Evaporative emission (EVAP) system -malfunction | Wiring, EVAP system hoses, EVAP canister,EVAP canister purge valve |
| P1444 | Evaporative emission (EVAP) system -low input | Wiring, EVAP pressure sensor, ECM |
| P1445 | Evaporative emission (EVAP) system -high input | Wiring, EVAP pressure sensor, ECM |
| P1450 | Evaporative emission (EVAP) system, vent control -circuit malfunction | Wiring, EVAP system hoses, EVAP canister purge valve, fuel filler cap blocked |
| P1451 | Evaporative emission (EVAP) canister purgevalve -circuit malfunction | Wiring, EVAP canister purge valve, ECM |
| P1452 | Evaporative emission (EVAP) system -unable to bleed fuel tank vacuum | Wiring, EVAP system hoses, EVAP canister purge valve, fuel filler cap blocked |
| P1455 | Evaporative emission (EVAP) system malfunction | Fuel filler cap blocked, EVAP system hoses |
| P1460 | Wide open throttle (WOT) relay, Ale circuit malfunction | Wiring, WOT relay, ECM |
| P1461 | Ale refrigerant pressure sensor -high voltage | Wiring, AlC refrigerant pressure sensor, ECM |
| P1462 | AlC refrigerant pressure sensor -low voltage | Wiring, AlC refrigerant pressure sensor, ECM |
| P1463 | AlC refrigerant pressure sensor -insufficientpressure change | Wiring, AlC system -mechanical fault, AlC refrigerant pressure sensor, AlC compressor clutch |
| P1464 | Ale demand out | Wiring, AlC ON -during self-test, WOT relay (AlC cut-out), ECM |
| P1469 | Frequent Ale compressor clutch cycling | Wiring, AlC system -mechanical fault |
| P1473 | Engine coolant blower motor -circuit malfunction | Wiring open circuit/short circuit to positive, engine coolant blower motor, variable load control module |
| P1474 | Engine coolant blower motor (low speed) control circuit malfunction | Wiring, engine coolant blower motor relay, ECM |
| P1477 | Engine coolant blower motor (medium speed) control circuit malfunction | Wiring, engine coolant blower motor relay, ECM |
| P1479 | Engine coolant blower motor (high speed) control circuit malfunction | Wiring, engine coolant blower motor relay, ECM |
| P1480 | Engine coolant blo'(/er motor (low speed) -with low speed fan ON | Wiring, engine coolant blower motor relay |
| P1481 | Engine coolant blower motor (low speed) -with high speed fan ON | Wiring, engine coolant blower motor relay |
| P1483 | Engine coolant blower motor -intermittent fault | Wiring, engine coolant blower motor, variable load control module |
| P1484 | Variable load control module -malfunction | Wiring open circuit, variable load control module |
| P1500 | Vehicle speed sensor (VSS) -circuit intermittent | Wiring, VSS, ECM |
| P1501 | Vehicle speed sensor (VSS) -out of self-test range | Electro-magnetic interference |
| P1502 | Vehicle speed sensor (VSS) -intermittent signal | Wiring, VSS/ABS wheel speed sensors |
| P1504 | Idle air control (lAC) valve -circuit malfunction | Wiring, lAC valve, intake system leaking, ECM |
| P1505 | Idle air control (lAC) system -air trim, at limit | Intake system leaking, air filter blocked, throttle body, lAC valve |
| P1506 | Idle air control (lAC) valve -over-speed error | Wiring, lAC valve, vacuum leaks, ECM |
| P1507 | Idle air control (lAC) valve -under-speed error | Wiring, lAC valve, hose blocked, ECM |
| P1512 | Intake manifold runner control (IMRC) module -malfunction, stuck closed – | Mechanical fault |
| P1513 | Intake manifold runner control (IMRC) module -malfunction, stuck closed – | Mechanical fault |
| P1516 | Intake manifold runner control (IMRC) module -input error (bank 1) | Wiring, mechanical fault |
| P1517 | Intake manifold runner control (IMRC) module -input error (bank 2) | Wiring, mechanical fault |
| P1518 | Intake manifold runner control (IMRC) module -malfunction, stuck open | Wiring, IMRC actuator, ECM |
| P1519 | Intake manifold runner control (IMRC) module -malfunction, stuck closed | Wiring, IMRC actuator, ECM |
| P1520 | Intake manifold runner control (IMRC) module -circuit malfunction | Mechanical fault, vacuum hoses, IMRC actuator, ECM |
| P1530 | AlC compressor clutch -circuit malfunction | Wiring open circuit/short circuit to positive, AlC compressor clutch, variable load control module |
| P1537 | Intake manifold runner control (IMRC) module -malfunction, stuck closed | Wiring, mechanical fault, ECM |
| P1538 | Intake manifold runner control (IMRC) module -malfunction, stuck closed | Wiring, mechanical fault, ECM |
| P1539 | AlC compressor clutch -circuit malfunction | Wiring, AlC compressor clutch, variable load control module |
| P1549 | Intake manifold air control system malfunction | Wiring, intake manifold air control solenoid, ECM |
| P1550 | Power steering pressure (PSP) sensormalfunction | Wiring, PSP sensor, ECM |
| P1565 | Cruise control system | Wiring, CPP switch, BPP switch, cruise control module, cruise control master switch, VSS |
| P1566 | Cruise control system | Wiring, CPP switch, BPP switch, cruise control module, cruise control master switch, VSS |
| P1567 | Cruise control system | Wiring, CPP switch, BPP switch, cruise control module, cruise control master switch, VSS |
| P1568 | Cruise control system | Wiring, CPP switch, BPP switch, cruise control module, cruise control master switch, VSS |
| P1572 I1J | Brake pedal’position (BPP) switch -out of self-test range | Wiring, lights control module, BPP switch, ECM |
| P1605 | ‘Keep alive’ memory test failure | Wiring, battery terminal corrosion, loose battery connection, ECM |
| P1625 | Variable load control module, power supply to engine coolant blower motor -circuit malfunction | Wiring, variable load control module |
| P1626 | Variable load control module, power supply to AlC system -circuit malfunction | Wiring, variable load control module |
| P1633 | ‘Keep alive’ power supply -voltage too low | Wiring, ECM |
| P1635 | Tire/axle ratio out of range | Incorrect tire size, incorrect axle ratio, incorrect vehicle 10 configuration |
| P1636 | Engine control module (ECM) -internal fault | ECM |
| P1640 | Diagnostic trouble codes stored | P-codes stored in another control module |
| P1641 | Fuel pump -circuit malfunction | Wiring, fuel pump relay, fuel pump, ECM |
| P1650 | Power steering pressure (PSP) switch -malfunction | Wiring, P5P switch, steering wheel turned during self-test, ECM |
| P1651 | Power steering pressure (PSP) switch -input | Wiring, vehicle towed with engine running, P5P switch, OTC not erased, ECM |
| P1700 | Transmission system -malfunction | Transmission |
| P1701 | Transmission system -reverse engagement error | Transmission |
| P1702 | Transmission range (TR) sensor -circuit intermittent | Wiring, TR sensor |
| P1703 | Brake pedal position (BPP) switch -out of self-test range | Wiring, brake pedal depressed during self-test, rear electronic module/lights control module, BPP switch, ECM |
| P1704 | Transmission range (TR) sensor -malfunction | Wiring, TR sensor |
| P1705 | Park/neutral position (PNP) switch/clutch pedal position (CPP) switch | Wiring, PNP switch, CPP switch, ECM |
| P1709 | Park/neutral position (PNP) switch/clutch pedal position (CPP) switch -out of self-test range | Wiring, PNP switch/CPP switch, ECM |
| P1710 | Transmission fluid temperature (TFT) sensor mid range failure | Wiring, TFT sensor |
| P1711 | Transmission fluid temperature (TFT) sensor out of self-test range | Wiring, TFT sensor, fluid level, ECM |
| P1713 | Transmission fluid temperature (TFT) sensor lowrange failure | Wiring, TFT sensor |
| P1714 | Shift solenoid (SS) A -inductive malfunction | Wiring, 55, ECMITCM |
| P1715 | Shift solenoid (SS) B -inductive malfunction | Wiring, 55, ECMITCM |
| P1716 | Shift solenoid (SS) C -inductive malfunction | Wiring, 55, ECMITCM |
| P1717 | Shift solenoid (SS) D -inductive malfunction | Wiring, 55, ECMITCM |
| P1718 | Transmission fluid temperature (TFT) sensor high range failure | Wiring, TFT sensor |
| P1719 | Overdrive speed sensor -circuit malfunction | Wiring, overdrive speed sensor, TCM |
| P1728 | Torque converter clutch (TCC) -slip fault | TCC |
| P1729 | 4x4L switch -malfunction | Wiring, four wheel drive shift control module, ECM |
| P1740 | Torque converter clutch (TCC) solenoid -circuitmalfunction | Wiring, TCC solenoid, ECMfTCM |
| P1741 | Torque converter clutch (TCC) -control error | Wiring, TCC, TCM |
| P1742 | Torque converter clutch (TCC) solenoid | Wiring, TCC solenoid |
| P1743 | Torque converter clutch (TCC) solenoid | Wiring, TCC solenoid |
| P1744 | Torque converter clutch (TCC) -malfunction | Wiring, TCC, TCM |
| P1745 | Transmission fluid pressure (TFP) solenoid circuitmalfunction | Wiring, TFP solenoid, TCM, ECM |
| P1746 | Transmission fluid pressure (TFP) solenoid -circuitmalfunction | Wiring, TFP solenoid, TCM, ECM |
| P1747 | Transmission fluid pressure (TFP) solenoid -circuit malfunction | Wiring short circuit, TFP solenoid, TCM |
| P1749 | Transmission fluid pressure (TFP) solenoid -malfunction | Wiring, TFP solenoid, TCM |
| P1751 | Shift solenoid (SS) A -performance | Wiring, 55 |
| P1754 | Coas’t clutch solenoid -circuit malfunction | Wiring, coast clutch solenoid |
| P1756 | Shift solenoid (SS) B -performance | Wiring, 55 |
| P1760 | Transmission fluid pressure (TFP) solenoid shortcircuit | Wiring, TFP solenoid, TCM |
| P1761 | Shift solenoid (SS) C -performance | Wiring, 55 |
| P1762 | Overdrive band failed/off | Transmission |
| P1767 | Torque converter clutch (TCC) -circuit malfunction | Wiring, TCC, TCM |
| P1780 | Overdrive selection switch | Wiring, transmission control switch, ECM |
| P1781 | 4x4L switch -out of self-test range | Wiring, four wheel drive shift control module, 4x4L switch, ECM |
| P1783 | Transmission fluid temperature (TFT) sensoroverheating condition | Wiring, TFT sensor, TCM, ECM |
| P1784 | Transmission, reverselfirst gear mechanical fault | Transmission |
| P1785 | Transmission, first/second gear -mechanical fault | Transmission |
| P1786 | Gear selection, 3-2 -downshift malfunction | Wiring, TR sensor, shift solenoids, transmission mechanical fault |
| P1787 | Gear selection, 2-1 -downshift malfunction | Wiring, TR sensor, shift solenoids, transmission mechanical fault |
| P1788 | Transmission shift control valve, 3-2 downshift!coastdown downshift -open circuit | Wiring, transmission shift control valve, TCM |
| P1789 | Transmission shift control valve, 3-2 downshift! coastdown downshift -short circuit | Wiring, transmission shift control valve, TCM |
| P1900 | Output shaft speed (OSS) sensor -circuit intermittent | Wiring, poor connection, OSS sensor, ECMfTCM |
| P1901 | Turbine shaft speed (TSS) sensor -circuit intermittent | Wiring, poor connection, TSS sensor, ECMfTCM |
| U1020 | CAN data bus, NC NC compressor clutch invalid or missing data | Wiring, NC trouble code(s) stored |
| U1021 | CAN data bus, NC communication error | Wiring, AlC trouble code(s) stored, ECM |
| U1039 | CAN data bus, antilock brake system (ASS) vehicle speed invalid or missing data | Wiring, ABS trouble code(s) stored |
| U1041 | CAN data bus, anti lock brake system(ASS)vehicle speed invalid or missing data | Wiring, ASS trouble code(s) stored |
| U1051 | CAN data bus, engine control module (ECM) brake signal invalid or missing data | Wiring, BPP switch, bulb(s) |
| U1073 | CAN data bus, cooling system -communication error | Wiring, variable load control module, ECM (alternative fuel) -if fitted, ECM |
| U1089 | CAN data bus, active suspension -invalid or .missing data | Wiring, active suspension trouble code(s) stored |
| U1098 | CAN data bus, antilock brake system (ASS) vehicle speed invalid or missing data | Wiring, ABS trouble code(s) stored |
| U1130 | CAN data bus, fuel pump -communication error | Wiring, instrument panel, ECM |
| U1131 | CAN data bus, fuel pump -communication error | Wiring, instrument panel, ECM |
| U1135 | CAN data bus, engine control module (ECM)ignition switch invalid or missing data | Wiring |
| U1147 | CAN data bus, alarm | Wiring, alarm system trouble code(s) stored |
| U1243 | CAN data bus, NC invalid or missing data | Wiring, AlC system trouble code(s) stored |
| U1256 | CAN data bus -communication error | Wiring, trouble code(s) stored in other control modules |
| U1262 | CAN data bus -communication error | Wiring, trouble code(s) stored in other control modules |
| U1341 | CAN data bus, NC vehicle speed invalid or missing data | Wiring, AlC trouble code(s) stored |
| U1451 | CAN data bus, alarm | Wiring, alarm system trouble code(s) stored |
| U2195 | CAN data bus, lights control module -invalid or missing data | Wiring, lights control module trouble code(s) stored |
| U2243 | CAN data bus, NC | Wiring, AlC system trouble code(s) stored |
