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Home >> Jeep >> 2008 >> Commander Overland, RWD >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P0128 To P0197 >> P0138-O2 Sensor 1/2 Circuit High >> Possible Causes
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Possible Causes

Possible Causes 
(K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO VOLTAGE
(K141) O2 1/2 SENSOR SIGNAL CIRCUIT OPEN
(K904) O2 RETURN DOWNSTREAM CIRCUIT OPEN
1/2 O2 SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding.