Diagnostic Trouble Code (Dtc) P1134 - Isuzu 1999 RODEO Workshop Manual

DIAGNOSTIC TROUBLE CODE (DTC) P1134 O2 SENSOR TRANSITION TIME
Circuit Description
The powertrain control module (PCM) monitors the
heated oxygen sensor (HO2S) activity for 90 seconds
after "Closed Loop" has been established. During the
monitoring period the PCM counts the number of times
that the HO2S responds from rich–to–lean and from
lean–to–rich and adds the amount of time it took to
complete all transitions. With this information, an average
time for all transitions can be determined. The PCM then
divides the rich–to–lean average by the lean–to–rich
average to obtain a ratio. If the HO2S transition time ratio
is not within this range, Diagnostic Trouble Code P1134
will be set, indicating that the oxygen sensor is not
responding as expected to changes in exhaust oxygen
content. DTC P1134 is a type B code.
Conditions for Setting the DTC
f No related Diagnostic Trouble Codes.
f Engine coolant temperature (ECT) is above 60°C
(140°F).
f Engine is operating in "Closed Loop".
f The engine has been running at least two minutes.
f Calculated air flow between 17 and 32 grams/sec.
f Canister purge duty cycle is greater than 2%.
f Engine speed is between 1500 RPM and 3500 RPM.
f Above conditions are present for a 1–second
monitoring period.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
RATIO (BANK 1 SENSOR 1)
f 90 seconds after "Closed Loop" has been enabled,
Bank 1 HO2S 1 transition ratio between lean–to–rich
and rich–to–lean is less than 0.4 or greater than 3.8.
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.
f "Open Loop" fuel control will be in effect.
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.
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 P1134 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.
f Diagnostic Trouble Code P1134 can be cleared by
using the Scan Tool's "Clear Info" function.
Diagnostic Aids
A malfunction in the HO2S heater ignition feed or ground
circuit may cause a Diagnostic Trouble Code P1133 to
set. Check HO2S heater circuitry for intermittent faults or
poor connections. If connections and wiring are OK and
6E1–323
D06RX046