LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2021 >> Gladiator Mojave, Part Time T/Case Control, Automatic Trans >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> 3.6L (GPEC 2A) - DTCS P1055 To P1496 >> DTC Troubleshooting >> P1128-Closed Loop Fueling Not Achieved - Bank 1 Upstream >> Possible Causes

Possible Causes

Possible Causes
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SENSOR HEATER OPERATION
O2 SIGNAL CIRCUIT
O2 RETURN CIRCUIT
OXYGEN (O2) SENSOR
ECT SENSOR OPERATION
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. Refer to  PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE  .