P1646 GMC Code - EVAP Vent Solenoid Output Circuit
Quick Answer
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. Common causes include Faulty EVAP Vent Solenoid, EVAP Vent Solenoid harness is open or shorted, EVAP Vent Solenoid circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1646 GMC indicates EVAP Vent Solenoid Output Circuit.
- Common causes
- Common causes include Faulty EVAP Vent Solenoid, EVAP Vent Solenoid harness is open or shorted, EVAP Vent Solenoid circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1646 GMC Description
What are the Possible Causes of the DTC P1646 GMC?
- Faulty EVAP Vent Solenoid
- EVAP Vent Solenoid harness is open or shorted
- EVAP Vent Solenoid circuit poor electrical connection
How to Fix the DTC P1646 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1646 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P1646 GMC Code
What does the OBDII code P1646 mean on a GMC vehicle?
P1646 indicates a problem with the EVAP Vent Solenoid Output Circuit, which controls the venting of fuel vapors from the fuel system.
What are common symptoms of code P1646 in GMC vehicles?
Symptoms may include a check engine light, increased fuel odor, reduced fuel efficiency, and difficulty passing emissions tests.
What causes the P1646 code to appear on GMC vehicles?
Common causes include a faulty EVAP vent solenoid, damaged wiring or connectors in the circuit, or a malfunctioning control module.
Can I drive my GMC vehicle with the P1646 code active?
While you can drive with this code, it may affect emissions and fuel efficiency. It’s best to address the issue promptly to avoid further damage.
How do you diagnose the P1646 code on a GMC vehicle?
Diagnosis involves inspecting the EVAP vent solenoid, checking wiring and connectors for damage, and testing the circuit with a multimeter.
How can the P1646 code be fixed on a GMC vehicle?
Repairs may include replacing the EVAP vent solenoid, repairing damaged wiring or connectors, or reprogramming the control module if necessary.
How much does it typically cost to repair a P1646 code on a GMC vehicle?
Costs vary, but replacing the EVAP vent solenoid typically ranges from $100 to $300, depending on parts and labor.
Can a faulty EVAP vent solenoid cause other problems besides the P1646 code?
Yes, it may lead to excessive fuel vapor buildup, which could cause increased emissions and potential damage to the fuel system.
How can I prevent the P1646 code from recurring on my GMC vehicle?
Regular maintenance, including inspecting wiring and connectors and ensuring proper operation of the EVAP system, can help prevent this code.
Will a P1646 code cause my GMC vehicle to fail an emissions test?
Yes, as this code affects the EVAP system, it can lead to failing an emissions test due to increased fuel vapor emissions.
Discuss the causes and fixes for P1646 GMC OBDII Code
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