Diagnostic Trouble Code (Dtc) P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) - Isuzu 1999 RODEO Workshop Manual

DIAGNOSTIC TROUBLE CODE (DTC) P0134 O2 SENSOR CIRCUIT NO ACTIV-
Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) high and low circuits. When measured
with a 10 MW digital voltmeter, this may display as low as
320 mV. The oxygen sensor varies the voltage within a
range of about 1000 mV when the exhaust is rich, down
through about 10 mV when exhaust is lean. The PCM
constantly monitors the HO2S signal during "Closed
Loop" operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse width
as necessary. If the Bank 1 HO2S 1 voltage remains at or
near the 450 mV bias for an extended period of time,
Diagnostic Trouble Code P0134 will be set, indicating an
open sensor signal or sensor low circuit. DTC P0134 is a
type B code.
Conditions for Setting the DTC
f No related Diagnostic Trouble Codes.
f Engine run time is longer than 120 seconds.
f Oxygen sensor heater has been determined to be
functioning properly, and the oxygen sensor has
warmed to operating temperature.
All the above conditions are met and the following
condition is met:
f Bank 1 HO2S 1 signal voltage remains between 400
mV and 500 mV for a total of 76.5 seconds over a
90–second period of time.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
ITY DETECTED (BANK 1 SENSOR 1)
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) the second time the fault is detected.
f The PCM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.
f "Open Loop" fuel control will be in effect.
Conditions for Clearing the MIL/DTC
f The PCM will turn the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.
f A history Diagnostic Trouble Code P0134 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.
f Diagnostic Trouble Code P0134 can be cleared by
using the Scan Tool's "Clear Info" function.
Diagnostic Aids
Check for the following conditions:
f Poor connection or damaged harness – Inspect the
harness connectors
improper mating, broken locks, improperly formed or
damaged terminals,
connection, and damaged harness.
f Faulty HO2S heater or heater circuit – With the ignition
ON engine OFF after a cooldown period, the HO2S 1
voltage displayed on the Tech 2 is normally 455–460
mV. A reading over 1000 mV indicates a signal line
shorted to voltage. A reading under 5 mV indicates a
6E1–153
D06RX046
for backed–out terminals,
poor terminal–to–wire