Diagnostic Trouble Code (Dtc) P0125 Insufficient Coolant Temperature For Closed Loop Fuel Control - Isuzu 1999 RODEO Workshop Manual

DIAGNOSTIC TROUBLE CODE (DTC) P0125 INSUFFICIENT COOLANT TEM-
PERATURE FOR CLOSED LOOP FUEL CONTROL
Circuit Description
To provide the best possible combination of driveability,
fuel economy, and emission control, a "Closed Loop"
air/fuel metering system is used. When the vehicle is first
started, the powertrain control module (PCM) controls
fuel delivery in "Open Loop" ignoring the heated oxygen
sensor (HO2S) signals and calculating air/fuel ratio based
on inputs from the engine coolant temperature, throttle
position, and mass air flow sensors.
If the PCM detects that the ECT sensor has not reached a
sufficient reading to achieve "Closed Loop" within a
specified amount of time, DTC P0125 will set. DTC
P0125 is a type B code.
Conditions for Setting the DTC
f No MAP, IAT, ECT, TP, Misfire, Injector, or VSS DTC
codes set.
All the above mentioned conditions are true and any
combination of the following three tests fail three times in
two consecutive ignition cycles (for a total of six failures):
Warm Case Test
f Start–up ECT value is less than 29°C (84°F).
f IAT is greater than 10°C (50°F).
f Accumulated airflow is greater than 1500 grams.
f Engine run time is greater than 90 seconds.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
f Time for coolant to reach stabilized "Closed Loop"
value is less than 120 seconds.
Cold Case Test
f IAT is between –7°C (20°F) and 10°C (50°F)
f Accumulated airflow is greater than 2000 grams.
f Engine run time is less than 225 seconds.
f Time for coolant to reach stabilized "Closed Loop"
value is less than 300 seconds.
Other Case Test
f IAT is between –30°C (–22°F) and –7°C (20°F).
f Accumulated airflow is greater than 3600 grams.
f Engine run time is less than 450 seconds.
f Time for coolant to reach stabilized "Closed Loop"
value is less than 600 seconds.
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 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.
6E1–141
D06RX044