| Scan code | Fault location | Probable cause |
| PO, P2,UO | Refer to OBO-II trouble code tables | – |
| P1192 | Intake air temperature (IAT) sensor -voltage low | Wiring, IAT sensor |
| P1193 | Intake air temperature (IAT) sensor -voltage high | Wiring, IAT sensor |
| P1195 | Heated oxygen sensor (H02S) 1, bank 1 slow response | Heating inoperative, wiring, H02S |
| P1196 | Heated oxygen sensor (H02S) 2, bank 1 slowresponse | Heating inoperative, wiring, H02S |
| P1281 | Engine temperature -low for long period | Wiring, cooling system, coolant thermostat, ECTsensor |
| P1282 | Fuel pump relay | Wiring open circuit/short circuit, fuel pump relay |
| P1290 | Compressed natural gas pressure sensor pressure high | Compressed natural gas system, wiring, compressed natural gas pressure sensor |
| P1292 | Compressed natural gas pressure sensor voltage high | Wiring, compressed natural gas pressure sensor |
| P1293 | Compressed natural gas pressure sensor voltage low | Wiring, compressed natural gas pressure sensor |
| P1294 | Idle speed control (ISC) system -rpm lower/ higher than expected | Wiring, air leak, throttle valve tight/sticking, lAC valve |
| P1295 | Throttle position (TP) sensor -supply voltage | Wiring, TP sensor, ECM |
| P1296 | Manifold absolute pressure (MAP) sensor supply voltage | Wiring, MAP sensor, ECM |
| P1297 | Manifold absolute pressure (MAP) sensor | Wiring, hose connection(s), MAP sensor |
| P1298 | System too lean -at prolonged wide open throttle | Intake/exhaust leak, MAP sensor, fuel pressure/pump, injector(s), H02S |
| P1299 | Manifold absolute pressure (MAP) sensor/throttle position (TP) sensor | Intake leak, hose connection(s), MAP sensor, TP sensor |
| P1388 | Engine control relay | Wiring open circuit/short circuit, engine control relay |
| P1389 | Engine control relay | Wiring open circuit, engine control relay |
| P1390 | Crankshaft position (CKP) sensor/camshaft position (CMP) sensor -signal synchronisation | Timing belt loose/jumped position, CKP sensor, CMP sensor |
| P1391 | Crankshaft position (CKP) sensor/camshaft position (CMP) sensor -intermittent signal | Wiring, poor connection, air gap, CKP sensor, CMP sensor |
| P1398 | Engine control module (ECM) -misfire detection limit reached | Wiring, poor connection, CKP sensor |
| P1486 | Evaporative emission (EVAP) system blockage detected | Hose connection(s), hose blocked/trapped, EVAP canister |
| P1488 | Engine control module (ECM) -auxiliary 5 volt output low . | Wiring, ECM |
| P1489 | Engine coolant blower motor relay | Wiring open circuit/short circuit, engine coolant blower motor relay -high speed |
| P1490 | Engine coolant blower motor relay | Wiring open circuit/short circuit, engine coolant blower motor relay -low speed |
| P1491 | Engine coolant blower motor relay -.circuit malfunction | Wiring open circuit/short circuit, engine coolant blower motor relay |
| P1492 | Ambient/battery temperature sensor -high input | Wiring short circuit to positive, ambient/ battery temperature sensor, ECM |
| P1493 | Ambient/battery temperature sensor -voltage low | Wiring, ambient/battery temperature sensor |
| P1494 | Evaporative emission (EVAP) leak detection pump -pressure switch | Wiring, hose leak!blockage, EVAP leak detection pump |
| P1495 | Evaporative emission (EVAP) leak detection pump solenoid | Wiring open circuit/short circuit, hose leak! blockage, EVAP leak detection pump solenoid |
| P1496 | Engine control module (ECM) -5 volt output low | ECM |
| P1594 | Alternator -voltage high | Wiring, battery, alternator |
| P1595 | Cruise control | Wiring open circuit/short circuit, hoses, cruise control master switch, cruise control vacuum switching valve |
| P1596 | Cruise control master switch -high voltage | Wiring, cruise control master switch |
| P1597 | Cruise control master switch -low voltage | Wiring, cruise control master switch |
| P1598 | AlC refrigerant pressure sensor -high input | Wiring, AlC refrigerant pressure too high (cooling fault/incorrectly charged), AlC refrigerant pressure sensor |
| P1599 | AlC refrigerant pressure sensor -low input | Wiring, AlC refrigerant pressure too low (incorrectly charged), AlC refrigerant pressure sensor |
| P1602 | Engine control module (ECM) not programmed | New ECM not programmed, incorrectly programmed, ECM |
| P1603 | Engine control module (ECM) -RAM link error | ECM |
| P1604 | Engine control module (ECM) -RAM read/ write error | ECM |
| P1607 | Engine control module (ECM) -shut down timer error | ECM |
| P1681 | CAN data bus, instrumentation -no signal | Wiring, instrumentation control module |
| P1682 | Alternator -voltage low | Wiring, battery, alternator drive belt, alternator |
| P1683 | Cruise control | Wiring, cruise control vacuum switching valve |
| P1684 | Engine control module (ECM) -supply voltage disconnected within last 50 ignition switch ON-OFF cycles | Wiring, battery |
| P1685 | Key not programmed into immobilizer control module | Wiring, ignition key not matched/damaged, immobilizer control module |
| P1686 | CAN data bus, immobilizer control module no signal | Wiring, immobilizer control module |
| P1687 | CAN data bus, instrumentation no signal | Wiring, instrumentation control module mechanical |
| P1695 | CAN data bus, body control module (BCM) no signal | Wiring, BCM |
| P1696 | Engine control module (ECM) -EEPROM error | ECM |
| P1697 | Engine control module (ECM) -EEPROM error | ECM |
| P1698 | CAN data bus, transmission control module (TCM) -no signal | Wiring, TCM |
| P1765 | Transmission system relay | Wiring open circuit/short circuit, transmission system relay, ECMITCM |
| P1899 | Park/neutral position (PNP) switch -input circuit malfunction | Wiring, PNP switch, ECMITCM |
