DTC P0125: Closed Loop Temp Not Reached
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION
. For circuit identification and wiring diagram, see WRANGLER
wiring diagram in WIRING DIAGRAMS article.
NOTE:
DTC P0125: CLOSED LOOP TEMP NOT REACHED is monitored for 10 minutes after engine is started. DTC may be stored in Powertrain Control Module (PCM) when PCM senses that Engine Coolant Temperature (ECT) sensor does not go to more than 18°F (-7.8°C) within 10 minutes after engine is started. Two trips are required to set this DTC. Possible causes are: defective ECT sensor, defective thermostat, defective PCM, defective connectors or defective wiring.
- Ensure ignition is off. Disconnect ECT sensor connector. See Figure
. Visually inspect connector for corroded, damaged, pushed-out or miswired terminals. Repair connector as necessary. Perform TEST VER-5A. If connector is okay, go to next step.NOTE: The following test is invalid if thermostat is stuck open.
- Start engine and allow it to idle until engine temperature is more than 180°F (82.2°C). Check thermostat operation. Replace thermostat if necessary. Perform TEST VER-5A. If thermostat is operating correctly, go to next step.NOTE: Engine temperature must be more than 80°F (26.6°C) in this step.
- Turn ignition off. Disconnect ECT sensor connector. Using an ohmmeter, check resistance across ECT sensor terminals. If resistance is less than 11,000 ohms, go to next step. If resistance is 11,000 ohms or more, replace ECT sensor. Perform TEST VER-5A.
- Ensure ignition is off. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Visually inspect connectors for corroded, damaged, pushed-out or miswired terminals. Repair connectors as necessary. Perform TEST VER-5A. If connectors are okay, go to next step.
- At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-5A.