DTC P0134: FRONT HO2S INSUFFICIENT ACTIVITY Isuzu Amigo II

Note. For circuit reference (Схема №6)

Circuit Description

PCM provides about .45 volt reference to Heated Oxygen Sensor (HO2S). HO2S sensor signal voltage varies from about one volt when exhaust is rich to about .1 volt when exhaust is lean. PCM reads and stores sensor voltage information and evaluates the voltage samples to determine amount of time sensor voltage is out of range. If HO2S voltage is out of predetermined range, DTC will set.

Conditions required to set DTC are

1. No related DTCs set.
2. ECT is above 140°F (60°C).
3. Engine has been running for at least 2 minutes.
4. HO2S heater has been determined to be functioning properly.
5. HO2S heater is functioning properly (HO2S has warmed to operating temperature).

Diagnostic Aids

Check for faulty connections or damaged harness. If connections and harness appear okay, observe front HO2S display on scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location. Check front HO2S heater operation. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.