AutoCodes – GMC – P1645 GMC

P1645 GMC Code - Evaporative Emission Purge Solenoid Output Circuit

Quick Answer

The Powertrain Control Module (PCM) contains Output Driver Modules (ODM) that provides 7 switchable ground outputs for operating solenoids, relays, indicator lights, and other devices. Common causes include Faulty Evaporative Emission Vent Solenoid, Evaporative Emission Vent Solenoid harness is open or shorted, Evaporative Emission 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: P1645 GMC indicates Evaporative Emission Purge Solenoid Output Circuit.
Common causes: Common causes include Faulty Evaporative Emission Vent Solenoid, Evaporative Emission Vent Solenoid harness is open or shorted, Evaporative Emission 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.

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Code Popularity 3,821

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Feb 24, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1645 GMC Description

The Powertrain Control Module (PCM) contains Output Driver Modules (ODM) that provides 7 switchable ground outputs for operating solenoids, relays, indicator lights, and other devices. Each of these ground outputs has fault lines that feedback to the PCM 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 zero volts, since it is grounding the output. If PCM sees zero volts when the output is off or 12 volts when the output is on, it sets a fault line low. The Diagnostic Trouble Code (DTC) is used to monitor the fault line of the EVAP control solenoid. With the engine runtime over 10 seconds, the PCM detects that the EVAP Solenoid Circuit line was low, conditions met for 2 seconds, and the DTC sets.

OBDII Code P1645 GMC - Evaporative Emission Purge Solenoid Output Circuit - AutoCodes.com — P1645 GMC Code - Evaporative Emission Purge Solenoid Output Circuit

What does this mean?

What are the Possible Causes of the DTC P1645 GMC?

Faulty Evaporative Emission Vent Solenoid
Evaporative Emission Vent Solenoid harness is open or shorted
Evaporative Emission Vent Solenoid circuit poor electrical connection

How to Fix the DTC P1645 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 P1645 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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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1645 GMC Code

1. What are common symptoms of OBDII code P1645 GMC?

- Common symptoms include rough idling, decreased fuel efficiency, and the illumination of the check engine light.

2. What does the OBDII code P1645 GMC indicate?

- The code indicates a problem with the Evaporative Emission Purge Solenoid Output Circuit.

3. What are possible causes of OBDII code P1645 GMC?

- Possible causes include a faulty purge solenoid, damaged wiring or connectors, or a problem with the vehicle's computer system.

4. How can I diagnose the issue related to code P1645 GMC?

- To diagnose the issue, you can use an OBDII scanner to retrieve the code, inspect the purge solenoid, check the wiring and connectors for any damage, and perform a smoke test to detect leaks in the evaporative emission system.

5. Can I still drive my vehicle with OBDII code P1645 GMC?

- It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to prevent further damage and ensure optimal performance.

6. How can I repair OBDII code P1645 GMC?

- Repairing the code typically involves replacing the faulty purge solenoid, repairing any damaged wiring or connectors, and clearing the code using an OBDII scanner.

7. Can I reset the check engine light after fixing OBDII code P1645 GMC?

- Yes, after fixing the issue causing the code, you can reset the check engine light using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes.

8. How much does it cost to fix OBDII code P1645 GMC at a repair shop?

- The cost of fixing this code at a repair shop can vary depending on the specific cause of the issue, but it typically ranges from $100 to $300 for parts and labor.

9. Are there any preventive maintenance tips to avoid OBDII code P1645 GMC?

- To prevent this code, it is recommended to follow the manufacturer's recommended maintenance schedule, regularly inspect the evaporative emission system components, and address any issues promptly.

10. Can a DIY enthusiast fix OBDII code P1645 GMC at home?

- Yes, if you have the necessary tools and knowledge, you can attempt to fix this code at home by following repair guides or tutorials specific to your vehicle make and model.