| Hummer Codes |
| Trouble Code |
Fault Location |
Probable Cause |
| P1101 | Intake airflow -incorrect | Wiring, mechanical fault, engine coolant temperature (EeT) 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, poor connections |
| P1107 | Manifold absolute pressure (MAP) sensor voltagelow, intermittent | Wiring short circuit to ground, poor connections |
| P1111 | Intake air temperature (lAT) sensor -voltage high, intermittent | Wiring open circuit/short to positive, poor connections |
| 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 |
| P1153 | Heated oxygen sensor (H02S) 1, bank 2 insufficient switching | Wiring, oxygen sensor heater, exhaust system leaking, H02S |
| P1154 | Heated oxygen sensor (H02S) 1, bank 2 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 |
| P1255 | Fuel pump control module -driver over- temperature | Fuel pump control module |
| P1380 | Antilock brake system (ABS)/traction control system (TCS), rough road signal to ECM -malfunction | ABS trouble code(s) stored |
| P1381 | Antilock brake system (ABS)/traction control system (TCS), rough road signal to ECM -no communication | Wiring, poor connections, ABS |
P1400 – P1499 (Emission control) | | P1400 | Cold start emission control -malfunction | Intake/exhaust leak/blockage, mechanical fault, idle speed control (ISC) system, ignition control, engine coolant temperature (ECT) sensor, H02S |
| P1514 | Throttle control unit, intake air flow -excessive | Throttle control unit, MAP sensor, CMP sensor signal, ECM |
| P1515 | Throttle command/actual throttle pOSition – signal variation | Wiring, throttle valve sticking, throttle control module |
| P1516 | Throttle command/actual throttle pOSition – signal variation | Wiring, throttle valve sticking, throttle control module |
| P1518 | Throttle control module/engine control module (ECM) -communication malfunction | Wiring, throttle control module, ECM |
P1600 – P1699 (ECM – computer output circuit) | | P1600 | Engine control module (ECM) -malfunction | Engine control module (ECM) |
| P1621 | Engine control module (ECM) memory performance | ECM |
| P1627 | Engine control module (ECM) -malfunction | Engine control module (ECM) |
| P1637 | Altemator ‘L’ terminal -circuit malfunction | Wiring open circuit/short circuit to ground, alternator, battery temperature sensor, ECM |
| P1638 | Altemator ‘F’ terminal -circuit malfunction | Wiring open circuit/short circuit to ground, alternator, ECM |
| P1680 | Engine control module (ECM) -malfunction | Engine control module (ECM) |
| P1681 | Engine control module (ECM) -malfunction | Engine control module (ECM) |
| P1682 | Throttle control module/engine control module (ECM) -ignition power supply variation | Wiring, ECM |
| P1683 | Engine control module (ECM) -malfunction | Engine control module (ECM) |
| P1810 | Transmission fluid pressure (TFP) switch -manual valve position | Fluid level low, wiring, selector lever linkage incorrectly adjusted, ECMITCM |
| P1815 | Transmission fluid pressure (TFP) switch invalid gear selection | Wiring, selector lever linkage incorrectly adjusted, TFP switch, ECM |
| P1816 | Transmission fluid pressure (TFP) switch -invalidgear selection | Wiring, selector lever linkage incorrectly adjusted,TFP switch, ECMITCM |
| P1860 | Torque converter clutch (TCC) solenoid, pulse width modulation (PWM) -circuit malfunction | Wiring open circuit/short circuit to ground, TCCsolenoid, ECM |
| P1875 | Transmission, 4WD low selection signal -circuit malfunction | Wiring, transmission, four wheel drive control module, ECM |
