EVAP Vent Solenoid Output Circuit
Table of contents
P1646 BUICK Possible Causes
- Faulty EVAP Vent Solenoid
- EVAP Vent Solenoid harness is open or shorted
- EVAP Vent Solenoid circuit poor electrical connection
How do I fix code P1646 BUICK?
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 P1646 BUICK code
The cost of diagnosing the P1646 BUICK 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.
When is the code detected
The Powertrain Control Module (PCM) has detected the EVAP Vent Solenoid circuit was low
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1646 BUICK Description
The Powertrain Control Module (PCM) contains chips called Output Driver Modules that provide 7 switchable ground outputs for operating solenoids, relays, telltales, and other devices. Each of these ground outputs has an internal fault line that feeds back to the PCMs microprocessor. When the output is OFF, the output driver should receive the 12 volts fed to the solenoid, relay, etc. When the output is ON, it should receive 0 volt since it is grounding the output. If it receives 0 volt when the output is OFF or 12 volts when the output is ON, it sets the fault line low.