PCV Heater Control Circuit Fault
Table of contents
P1489 MERCURY Possible Causes
- Faulty Positive Crankcase Ventilation (PCV) Heater
- Positive Crankcase Ventilation Heater harness is open or shorted
- Positive Crankcase Ventilation Heater circuit poor electrical connection
How do I fix code P1489 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P1489 MERCURY code
The cost of diagnosing the P1489 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1489 MERCURY Description
When the intake air temperature is less than 0°C (32°F) the Powertrain Control Module (PCM) grounds the Positive Crankcase Ventilation Valve Heater Control (PCVHC) circuit and turns the heater ON. When the intake air temperature exceeds 9°C (48°F) the heater is turned OFF. The PCV Heater is also off when the engine is not running to prevent unnecessary battery drain. The heater is also off if the vehicle charging system is greater than 16 volts. This minimizes heater element overload.
The Diagnostic Trouble Code (DTC) sets when the PCM detects the actual PCVHC circuit voltage is less than or greater than the desired voltage.