Chevrolet OBD / OBD2 Codes >> Cobalt – Equinox – HHR – Impala – Malibu – Monte Carlo – Tahoe – Uplander

ModelYearEngine identificationSystem
Cobalt 2.0/2.2/2.4L2005-09VIN  position 8 = A/B/F/M/PGM
Equinox 3.4/3.6L2005-09VIN  position 8 = 7/FGM
HHR 2.0/2.2/2.4L2006-09VIN  position 8 = 5/A/B/F/MGM
Impala 3.5/3.9/5.3L2006-09VIN  position 8 =  1/3/8/C/K/NGM
Malibu 3.9L2006-07VIN  position 8 = 1GM
Monte Carlo 3.5/3.9/5.3L2006-07VIN  position 8 = 1/8/CGM
Tahoe 4.8/5.3/6.0L2007-09VIN  position 8 = 5/C/J/OGM
Uplander 3.5/3.9L2005·08VIN  position 8 = 1/LGM

General information

  • Malfunction indicator lamp (MIL) will illuminate or flash if certain faults are recorded.
  • ECM operates in backup mode if sensors fail , to enable vehicle to be driven to repair shop.


  • Trouble codes can only be displayed by using a Scan Tool connected to the data link connector (DLC) [1].


  • After the faults have been rectified, the manufacturer recommends that trouble codes are erased by using a Scan Tool connected to the data link connector (DLC).

Trouble code  identification

Scan codeFault locationProbable cause
PO, P2, UORefer to OBO-II trouble code tables
P1011Intake camshaft position (CMP) actuator, bank 1 -incorrect park positionEngine oil level/pressure, mechanical fault
P1012Exhaust camshaft position (CMP) actuator, bank 1-incorrect park positionEngine oil level/pressure, mechanical fault
P1014Exhaust camshaft position (CMP) actuator, bank 2-incorrect park positionEngine oil level/pressure, mechanical fault
P1101Intake airflow -incorrectWiring, mechanical fault, engine coolant temperature (ECT) sensor, barometric pressure (BARO) sensor, intake air temperature (IAT)sensor, manifold absolute pressure (MAP) sensor,mass air flow (MAF) sensor, throttle position (TP)switch
P1106Manifold absolute pressure (MAP) sensor voltage high, intermittentWiring open circuit/short circuit to positive, poorconnections
P1107Manifold absolute pressure (MAP) sensor voltage low, intermittentWiring short circuit to ground, poor connections
P1111Intake air temperature (IAT) sensor -voltage high, intermittentWiring open circuit/short to positive, poorconnections
P1112Intake air temperature (IAT) sensor -voltage low, intermittentWiring short circuit to ground
P1114Engine coolant temperature (ECT) sensor voltage low, intermittentWiring short circuit to ground, poor connections
P1115Engine coolant temperature (ECT) sensor voltage high, intermittentWiring open circuit/short to positive, poor connections
P1125Accelerator pedal position (APP) sensor 1/2 signal malfunctionWiring, APP sensor, ECM
P1133Heated oxygen sensor (H02S) 1, bank 1 insufficient switchingWiring, exhaust system leaking, H02S
P1134Heated oxygen sensor (H02S) 1, bank 1 -slow responseWiring, oxygen sensor heater, exhaust system leaking, H02S
P1174Heated oxygen sensor (H02S) 1, bank 1 mixture variation between cylindersIntake/exhaust leak/blockage, mechanical fault,ignition control, H02S
P1175Heated oxygen sensor (H02S) 1, bank 2 mixture variation between cylindersIntake/exhaust leak/blockage, mechanical fault,ignition control, H02S
P1182Supercharger (SC) boost pressure sensor malfunctionWiring, intake/exhaust leak/blockage, SC boost pressure sensor, SC bypass valve, BARO sensor,IAT sensor, MAP sensor, MAF sensor, ECM
P1183Supercharger (SC) boost pressure sensor voltage lowWiring, SC boost pressure sensor, ECM
P1184Supercharger (SC) boost pressure sensor voltage highWiring, SC boost pressure sensor, ECM
P1380Antilock brake system (ABS)/traction control system (TCS), rough road signal to engine control module (ECM) -malfunctionABS trouble code(s) stored
P1381Antilock brake system (ABS)/traction control system (TCS), rough road signal to engine control module (ECM) -no communicationWiring, poor connections, ABS
P1400Cold start emission control -malfunctionIntake/exhaust leak/blockage, mechanical fault, idlespeed control (ISC) system, ignition control, engine coolant temperature (ECT) sensor, H02S
P1404Exhaust gas recirculation (EGR) valve not fully closingWiring, poor connections, EGR valve position sensor, EGR solenoid
P1516Throttle command/actual throttle position signal variationWiring, throttle valve sticking, throttle control module
P1551Throttle valve -rest position incorrectWiring, throttle body mechanical fault, throttle body, ECM ,
P1600Engine control module (ECM) -malfunctionECM
P16F3Engine control module (ECM) -malfunctionECM
P1621Engine control module (ECM) -malfunctionECM
P1627Engine control module (ECM) -malfunctionECM
P1633Engine control module (ECM), ignition supply voltageFuse, wiring open circuit, ECM
P1640Engine control module, output driver 1 -supplyv oltage highWiring, loose alternator connection, alternator
P1650Engine control module, output driver 2 -supply voltage highWiring, loose alternator connection, alternator
P1660Engine control module, output driver 3 -supply voltage highWiring, loose alternator connection, alternator
P1668Alternator ‘L’ terminal -circuit malfunctionWiring, voltage regulator, alternator, ECM
P167AECM -internal circuit malfunction, heated oxygen sensor (H02S) 1, bank 1ECM
P1670ECM -internal circuit malfunction, ignition coilECM
P1680Engine control module (ECM) -malfunctionECM
P1681Engine control module (ECM) -malfunctionECM
P1682Engine control module (ECM) -ignition power supply variationWiring, EC relay, starter motor relay, ECM
P1683Engine control module (ECM) -malfunctionECM
P1700Transmission control module (TCM) -MIL request circuit malfunctionOBO II TCM trouble codes stored
P1719Transmission control module (TCM) -detects excessive variation between transmission input/output shaft speed sensorsTransmission fluid level, line pressure, stuck/sticking SS
P1779Engine control module (ECM), torque reduction signal via controller area network (CAN) data bus -out of rangeWiring, TCM, ECM
P1780Engine control module (ECM), controller area network (CAN) data bus -lost communication with transmission control module (TCM)Wiring, ECM
P1781Engine control module (ECM), torque reduction signal -out of rangeWiring, TCM, ECM
P1791Engine control module (ECM), accelerator pedal position (APP) sensor signal via controller area network (CAN) data bus -out of rangeWiring, APP sensor, TCM, ECM
P1792Engine control module (ECM), engine coolant temperature (ECT) sensor signal via controller area network (CAN) data bus -out of rangeWiring, ECT, TCM, ECM
P1810Transmission fluid pressure (TFP) switch manual valve positionFluid level low, wiring, selector lever linkage incorrectly adjusted, ECMITCM
P1811Shift time too long -adaptation limit reachedFluid level low, transmission mechanical fault
P1816Transmission fluid pressure (TFP) switch -invalidgear selectionWiring, selector lever linkage incorrectly adjusted, TFP switch, ECMITCM
P1818Transmission fluid pressure (TFP) switch -invalidgear selectionWiring, selector lever linkage incorrectly adjusted, TFP switch, ECMITCM
P1819Transmission range (TR) switch, signals ‘AlBIC &P’ -signal variationWiring, TR switch
P1820Transmission range (TR) switch, signal ‘A’ voltage lowWiring short to ground, TR switch
P1822Transmission range (TR) switch, signal ‘B’ voltage highWiring, TR switch
P1823Transmission range (TR) switch, signal ‘P’ voltagelowWiring short to ground, TR switch
P1825Transmission range (TR) switch, signals ‘AlBIC &P’ incorrect signalWiring, TR switch
P1826Transmission range (TR) switch, signal ‘C’ voltage highWiring, TR switch
P1868Transmission fluid lifeReplace transmission fluid and filter
P1887Torque converter clutch (TCC) solenoid release switch -circuit malfunctionWiring open circuit, TCC solenoid release switch,ECMITCM
P3400Cylinder cut-out system -malfunctionWiring, intake system leaking, mechanical fault,MAF sensor, MAP sensor, TP sensor, ECM
P3401Cylinder cut-out solenoid, cylinder 1 malfunctionWiring, cylinder cut-out solenoid, mechanical fault,ECM
P3425Cylinder cut-out solenoid, cylinder 4 malfunctionWiring, cylinder cut-out solenoid, mechanical fault, ECM
P3441Cylinder cut-out solenoid, cylinder 6 malfunctionWiring, cylinder cut-out solenoid, mechanical fault, ECM
P3449Cylinder cut-out solenoid, cylinder 7 malfunctionWiring, cylinder cut-out solenoid, mechanical fault, ECM
The following actions may also set trouble codes:
  • Turning the engine OFF while the accelerator pedal is pressed.
  • Turning the engine OFF while driving.
  • Pressing the accelerator pedal to start the engine.