Chrysler PT Cruiser 2001 Service Manual Supplement page 2529

P0125-CLOSED LOOP TEMP NOT REACHED —
TEST
3 Note: This test works best if performed on a cold engine (cold soaked).
Turn the ignition on.
With the DRB, read the ENG COOLANT TMP DEG value. If the engine was allowed
to sit overnight (cold soak), the engine temperature value should be a sensible value
that is close to the surrounding temperature (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 thermom-
eter.
Note: As the engine warms up to operating temperature, the actual coolant
temperature (thermometer reading) and the ENG COOLANT TMP DEG
value on the DRB 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 4
→ Replace the thermostat.
No
4 Did the ENG COOLANT TMP DEG value increase smoothly and reach at least 82°
C (180° F)?
Yes → Test Complete.
→ Check the ECT wiring for high resistance. If OK, replace the
No
5 Turn the ignition off.
NOTE: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any Technical Service Bulletins (TSB) that may apply.
Perform a wiggle test on the related wiring harnesses with the engine running.
Watch for the Good Trip Counter to change to 0.
Were any problems found?
Yes → Repair wiring harness/connectors as necessary.
→ Test Complete.
No
ACTION
Engine Coolant Temperature Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
DRIVEABILITY - GAS
Continued
69
APPLICABILITY
All
All
All