P0125 on Chrysler 300
Factory diagnostic protocol and troubleshooting wire for fault code P0125 specifically for the Chrysler 300 (2020–2025, 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)).
1. Symptoms of P0125 on Chrysler 300
When the Engine Control Module (ECM/PCM) on your Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)) logs fault code P0125, drivers commonly observe:
2. Most Likely Causes on Chrysler 300
Historical warranty claims and technical repair bulletins for Chrysler 300 point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Chrysler 300
Check that engine coolant is at full mark and no external radiator or hose leaks exist. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Start cold engine and watch ECT climb. If it plateaus below 170°F (77°C) while driving, thermostat is stuck open. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Drain 1 gallon of coolant, remove thermostat housing bolts, install new OEM temperature-rated thermostat (typically 180°F–195°F) with jiggle valve at 12 o'clock. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Fill cooling system with 50/50 prediluted coolant, run engine with spill-free funnel to purge air bubbles. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Verify scan tool Fuel System Status changes from 'Open Loop' to 'Closed Loop' within 5 minutes. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Equipment for Diagnosing Chrysler 300 (P0125)
OEM Thermostat & Gasket Assembly
Direct-replacement thermostat calibrated to factory operating temperature for Chrysler 300.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Chrysler 300
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Chrysler 300:
4. Chrysler 300 P0125 FAQs
What causes code P0125 to trigger on a Chrysler 300?
On the Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)), P0125 is most frequently caused by Thermostat stuck open or opening prematurely or Low engine coolant level / air pocket around ECT sensor.
Where is the OBD-II port located on my Chrysler 300?
On the Chrysler 300, the 16-pin DLC diagnostic connector is located Under driver side dash near left knee panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Chrysler 300 with code P0125?
Yes, for short distances. Fuel economy will drop 15–25% as the engine remains trapped in open-loop enrichment. Given that P0125 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.