Chevrolet >> Cobalt – Equinox – HHR – Impala – Malibu – Monte Carlo – Tahoe – Uplander

Model Year Engine identification System
Cobalt 2.0/2.2/2.4L 2005-09 VIN  position 8 = A/B/F/M/P GM
Equinox 3.4/3.6L 2005-09 VIN  position 8 = 7/F GM
HHR 2.0/2.2/2.4L 2006-09 VIN  position 8 = 5/A/B/F/M GM
Impala 3.5/3.9/5.3L 2006-09 VIN  position 8 =  1/3/8/C/K/N GM
Malibu 3.9L 2006-07 VIN  position 8 = 1 GM
Monte Carlo 3.5/3.9/5.3L 2006-07 VIN  position 8 = 1/8/C GM
Tahoe 4.8/5.3/6.0L 2007-09 VIN  position 8 = 5/C/J/O GM
Uplander 3.5/3.9L 2005·08 VIN  position 8 = 1/L GM

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 code Fault location Probable cause
PO, P2, UO Refer to OBO-II trouble code tables
P1011 Intake camshaft position (CMP) actuator, bank 1 -incorrect park position Engine oil level/pressure, mechanical fault
P1012 Exhaust camshaft position (CMP) actuator, bank 1-incorrect park position Engine oil level/pressure, mechanical fault
P1014 Exhaust camshaft position (CMP) actuator, bank 2-incorrect park position Engine oil level/pressure, mechanical fault
P1101 Intake airflow -incorrect Wiring, 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
P1106 Manifold absolute pressure (MAP) sensor voltage high, intermittent Wiring open circuit/short circuit to positive, poorconnections
P1107 Manifold absolute pressure (MAP) sensor voltage low, intermittent Wiring short circuit to ground, poor connections
P1111 Intake air temperature (IAT) sensor -voltage high, intermittent Wiring open circuit/short to positive, poorconnections
P1112 Intake air temperature (IAT) sensor -voltage low, intermittent Wiring short circuit to ground
P1114 Engine coolant temperature (ECT) sensor voltage low, intermittent Wiring short circuit to ground, poor connections
P1115 Engine coolant temperature (ECT) sensor voltage high, intermittent Wiring open circuit/short to positive, poor connections
P1125 Accelerator pedal position (APP) sensor 1/2 signal malfunction Wiring, APP sensor, ECM
P1133 Heated oxygen sensor (H02S) 1, bank 1 insufficient switching Wiring, exhaust system leaking, H02S
P1134 Heated oxygen sensor (H02S) 1, bank 1 -slow response Wiring, oxygen sensor heater, exhaust system leaking, H02S
P1174 Heated oxygen sensor (H02S) 1, bank 1 mixture variation between cylinders Intake/exhaust leak/blockage, mechanical fault,ignition control, H02S
P1175 Heated oxygen sensor (H02S) 1, bank 2 mixture variation between cylinders Intake/exhaust leak/blockage, mechanical fault,ignition control, H02S
P1182 Supercharger (SC) boost pressure sensor malfunction Wiring, intake/exhaust leak/blockage, SC boost pressure sensor, SC bypass valve, BARO sensor,IAT sensor, MAP sensor, MAF sensor, ECM
P1183 Supercharger (SC) boost pressure sensor voltage low Wiring, SC boost pressure sensor, ECM
P1184 Supercharger (SC) boost pressure sensor voltage high Wiring, SC boost pressure sensor, ECM
P1380 Antilock brake system (ABS)/traction control system (TCS), rough road signal to engine control module (ECM) -malfunction ABS trouble code(s) stored
P1381 Antilock brake system (ABS)/traction control system (TCS), rough road signal to engine control module (ECM) -no communication Wiring, poor connections, ABS
P1400 Cold start emission control -malfunction Intake/exhaust leak/blockage, mechanical fault, idlespeed control (ISC) system, ignition control, engine coolant temperature (ECT) sensor, H02S
P1404 Exhaust gas recirculation (EGR) valve not fully closing Wiring, poor connections, EGR valve position sensor, EGR solenoid
P1516 Throttle command/actual throttle position signal variation Wiring, throttle valve sticking, throttle control module
P1551 Throttle valve -rest position incorrect Wiring, throttle body mechanical fault, throttle body, ECM ,
P1600 Engine control module (ECM) -malfunction ECM
P16F3 Engine control module (ECM) -malfunction ECM
P1621 Engine control module (ECM) -malfunction ECM
P1627 Engine control module (ECM) -malfunction ECM
P1633 Engine control module (ECM), ignition supply voltage Fuse, wiring open circuit, ECM
P1640 Engine control module, output driver 1 -supplyv oltage high Wiring, loose alternator connection, alternator
P1650 Engine control module, output driver 2 -supply voltage high Wiring, loose alternator connection, alternator
P1660 Engine control module, output driver 3 -supply voltage high Wiring, loose alternator connection, alternator
P1668 Alternator ‘L’ terminal -circuit malfunction Wiring, voltage regulator, alternator, ECM
P167A ECM -internal circuit malfunction, heated oxygen sensor (H02S) 1, bank 1 ECM
P1670 ECM -internal circuit malfunction, ignition coil ECM
P1680 Engine control module (ECM) -malfunction ECM
P1681 Engine control module (ECM) -malfunction ECM
P1682 Engine control module (ECM) -ignition power supply variation Wiring, EC relay, starter motor relay, ECM
P1683 Engine control module (ECM) -malfunction ECM
P1700 Transmission control module (TCM) -MIL request circuit malfunction OBO II TCM trouble codes stored
P1719 Transmission control module (TCM) -detects excessive variation between transmission input/output shaft speed sensors Transmission fluid level, line pressure, stuck/sticking SS
P1779 Engine control module (ECM), torque reduction signal via controller area network (CAN) data bus -out of range Wiring, TCM, ECM
P1780 Engine control module (ECM), controller area network (CAN) data bus -lost communication with transmission control module (TCM) Wiring, ECM
P1781 Engine control module (ECM), torque reduction signal -out of range Wiring, TCM, ECM
P1791 Engine control module (ECM), accelerator pedal position (APP) sensor signal via controller area network (CAN) data bus -out of range Wiring, APP sensor, TCM, ECM
P1792 Engine control module (ECM), engine coolant temperature (ECT) sensor signal via controller area network (CAN) data bus -out of range Wiring, ECT, TCM, ECM
P1810 Transmission fluid pressure (TFP) switch manual valve position Fluid level low, wiring, selector lever linkage incorrectly adjusted, ECMITCM
P1811 Shift time too long -adaptation limit reached Fluid level low, transmission mechanical fault
P1816 Transmission fluid pressure (TFP) switch -invalidgear selection Wiring, selector lever linkage incorrectly adjusted, TFP switch, ECMITCM
P1818 Transmission fluid pressure (TFP) switch -invalidgear selection Wiring, selector lever linkage incorrectly adjusted, TFP switch, ECMITCM
P1819 Transmission range (TR) switch, signals ‘AlBIC &P’ -signal variation Wiring, TR switch
P1820 Transmission range (TR) switch, signal ‘A’ voltage low Wiring short to ground, TR switch
P1822 Transmission range (TR) switch, signal ‘B’ voltage high Wiring, TR switch
P1823 Transmission range (TR) switch, signal ‘P’ voltagelow Wiring short to ground, TR switch
P1825 Transmission range (TR) switch, signals ‘AlBIC &P’ incorrect signal Wiring, TR switch
P1826 Transmission range (TR) switch, signal ‘C’ voltage high Wiring, TR switch
P1868 Transmission fluid life Replace transmission fluid and filter
P1887 Torque converter clutch (TCC) solenoid release switch -circuit malfunction Wiring open circuit, TCC solenoid release switch,ECMITCM
P3400 Cylinder cut-out system -malfunction Wiring, intake system leaking, mechanical fault,MAF sensor, MAP sensor, TP sensor, ECM
P3401 Cylinder cut-out solenoid, cylinder 1 malfunction Wiring, cylinder cut-out solenoid, mechanical fault,ECM
P3425 Cylinder cut-out solenoid, cylinder 4 malfunction Wiring, cylinder cut-out solenoid, mechanical fault, ECM
P3441 Cylinder cut-out solenoid, cylinder 6 malfunction Wiring, cylinder cut-out solenoid, mechanical fault, ECM
P3449 Cylinder cut-out solenoid, cylinder 7 malfunction Wiring, 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.