Chrysler 300M 2002 Service Manual page 2514

P0125-INSUFFICIENT COOLANT TEMP FOR CLOSED-LOOP FUEL CON -
TROL —
Continued
TEST
2 Note: This test works best if performed on a cold engine (cold soak)
Ignition on, engine not running.
With the DRBIII , read the Eng Coolant Tmp Deg value. If the engine was allowed
to sit overnight (cold soak), the temperature value should be a sensible value that is
somewhere close to the ambient temperature.
Note: If engine coolant temperature is above 82°C (180°F), allow the engine
to cool until 65°C (150°F) is reached.
Start the Engine.
During engine warm-up monitor the Eng Coolant Tmp Deg value. The temp deg
value change should be a smooth transition from start up to normal operating temp
82°C (180°F) . Also monitor the actual coolant temperature with a thermometer.
NOTE: As the engine warms up to operating temperature, the actual coolant
temperature (thermometer reading) and the Eng Coolant Tmp Deg in the
DRB values should stay relatively close to each other.
Using the appropriate service information, determine the proper opening tempera-
ture of the thermostat.
Did the thermostat open at the proper temperature?
Yes → Go To 3
→ Replace the thermostat.
No
3 Ignition on, engine not running.
With the DRBIII , read the Eng Coolant Tmp Deg value. If the engine was allowed
to sit overnight (cold soak), the temperature value should be a sensible value that is
somewhere close to the ambient temperature.
Note: If engine coolant temperature is above 82°C (180°F), allow the engine
to cool until 65°C (150°F) is reached.
Start the Engine.
During engine warm-up monitor the Eng Coolant Tmp Deg value. The temp deg
value change should be a smooth transition from start up to normal operating temp
82°C (180°F) . Also monitor the actual coolant temperature with a thermometer.
NOTE: As the engine warms up to operating temperature, the actual coolant
temperature (thermometer reading) and the Eng Coolant Tmp Deg in the
DRB values should stay relatively close to each other.
Is the thermometer reading relatively close to the DRBIII ECT reading?
Yes → Test Complete.
→ Replace the Engine Coolant Temperature Sensor.
No
ACTION
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
DRIVEABILITY - NGC
85
APPLICABILITY
All
All