Diagnostic Aids

A shifted (out-of-calibration) ECT sensor is indicated when Code P0125 is set. An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for:

• Poor Connection Or Damaged Harness:  Inspect PCM harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.
• Intermittent Test:  If connections and harness check okay, monitor a DVOM connected between PCM terminals while moving related connectors and wiring harness. If failure is induced, voltage reading will change. This may assist in isolating the location of the malfunction.

Fig 1: Code P0125A Schematic (Regal) Coolant Temperature Sensor Closed Loop Minimum Temperature Not Met

Fig 2: Code P0125A Flow Chart (Regal) Coolant Temperature Sensor Closed Loop Minimum Temperature Not Met