P0691 2014 GMC Sierra Code - Cooling Fan Speed Output Circuit Low Voltage
Quick Answer
The P0691 diagnostic trouble code (DTC) for a 2014 GMC Sierra indicates a problem with the cooling fan speed output circuit having low voltage. Common causes include Faulty cooling fan motor: A defective cooling fan motor can result in low voltage output in the cooling fan speed output circuit, Damaged wiring or connectors: Corroded or damaged wiring and connectors in the cooling fan speed output circuit can disrupt the voltage flow, Malfunctioning cooling fan control module: A failing cooling fan control module may not regulate the fan speed properly, leading to low voltage issues. 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
- P0691 2014 GMC Sierra indicates Cooling Fan Speed Output Circuit Low Voltage.
- Common causes
- Common causes include Faulty cooling fan motor: A defective cooling fan motor can result in low voltage output in the cooling fan speed output circuit, Damaged wiring or connectors: Corroded or damaged wiring and connectors in the cooling fan speed output circuit can disrupt the voltage flow, Malfunctioning cooling fan control module: A failing cooling fan control module may not regulate the fan speed properly, leading to low voltage issues.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P0691 2014 GMC Sierra Description
The P0691 diagnostic trouble code (DTC) for a 2014 GMC Sierra indicates a problem with the cooling fan speed output circuit having low voltage. In modern vehicles, the cooling fan plays a crucial role in maintaining the engine's optimal operating temperature by dissipating excess heat. The cooling fan speed output circuit is responsible for controlling the speed of the cooling fan based on the engine's temperature. When the voltage in this circuit drops below the specified range, it triggers the P0691 code.
Common Causes of P0691 2014 GMC Sierra
- Faulty cooling fan motor: A defective cooling fan motor can result in low voltage output in the cooling fan speed output circuit.
- Damaged wiring or connectors: Corroded or damaged wiring and connectors in the cooling fan speed output circuit can disrupt the voltage flow.
- Malfunctioning cooling fan control module: A failing cooling fan control module may not regulate the fan speed properly, leading to low voltage issues.
- ECM malfunction: A malfunction in the engine control module (ECM) can also cause low voltage in the cooling fan speed output circuit.
- Overheating: Excessive heat exposure can damage components in the cooling fan speed output circuit, leading to low voltage readings.
Symptoms of P0691 2014 GMC Sierra
- Engine overheating: One of the most common symptoms associated with the P0691 code is engine overheating due to inadequate cooling fan operation.
- Illuminated Check Engine Light: The vehicle's onboard diagnostic system may trigger the Check Engine Light to alert the driver of a potential issue with the cooling fan speed output circuit.
- Reduced air conditioning performance: A malfunctioning cooling fan can impact the air conditioning system's efficiency, leading to reduced cooling performance.
- Increased engine temperature fluctuations: The engine temperature gauge may show erratic fluctuations if the cooling fan speed output circuit is not functioning correctly.
- Unusual engine noises: In some cases, a failing cooling fan may produce unusual noises such as grinding or squealing sounds.
How to Fix P0691 2014 GMC Sierra
- Diagnose the issue: Use a diagnostic scanner to retrieve the trouble codes and perform a thorough inspection of the cooling fan speed output circuit to identify the root cause of the problem.
- Test the cooling fan motor: Check the cooling fan motor for proper operation and replace it if it is found to be faulty.
- Inspect wiring and connectors: Examine the wiring and connectors in the cooling fan speed output circuit for any damage or corrosion, and repair or replace as needed.
- Check the cooling fan control module: Test the cooling fan control module for proper functionality and replace it if it is malfunctioning.
- Verify ECM operation: Ensure the engine control module (ECM) is functioning correctly and reprogram or replace it if necessary to address the low voltage issue in the cooling fan speed output circuit.
Cost to Fix P0691 2014 GMC Sierra
The typical repair costs for addressing a P0691 code on a 2014 GMC Sierra can vary depending on the specific cause of the issue. In general, replacing a cooling fan motor can cost between $200 and $500, while repairing wiring or connectors may range from $100 to $300. Replacing a cooling fan control module can cost around $300 to $600, and addressing an ECM malfunction may range from $500 to $1000. Overall, the total repair cost for resolving a P0691 code could range from $300 to $1500, including parts and labor.
Need more information about the P0691 2014 GMC Sierra code?
Need more information on how to fix the P0691 2014 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0691 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0691 2014 GMC Sierra Code
1. What does the OBDII code P0691 mean on a 2014 GMC Sierra?
The P0691 code indicates a low voltage issue in the cooling fan speed output circuit, which affects the proper operation of the cooling fan.
2. What are the common symptoms of the P0691 code in a 2014 GMC Sierra?
Common symptoms include engine overheating, an illuminated check engine light, cooling fan not functioning, and possible A/C performance issues.
3. What causes the P0691 code to occur in a 2014 GMC Sierra?
Typical causes include a faulty cooling fan relay, damaged wiring or connectors in the cooling fan circuit, a defective cooling fan motor, or a malfunctioning Powertrain Control Module (PCM).
4. Can I drive my 2014 GMC Sierra with the P0691 code?
Driving with the P0691 code is not recommended, as it can lead to engine overheating and potential damage if the cooling fan is not operating properly.
5. How do I diagnose the P0691 code on my 2014 GMC Sierra?
Diagnosis involves checking the cooling fan relay, inspecting wiring and connectors for damage, testing the cooling fan motor, and using a multimeter to measure circuit voltage.
6. How can I fix the P0691 code on a 2014 GMC Sierra?
Repairs may include replacing a faulty cooling fan relay, repairing damaged wiring, replacing the cooling fan motor, or reprogramming or replacing the PCM if necessary.
7. Is the cooling fan relay a common culprit for the P0691 code?
Yes, a faulty cooling fan relay is a common cause of the P0691 code and should be one of the first components inspected.
8. Will clearing the P0691 code with a scanner fix the issue?
Clearing the code may temporarily turn off the check engine light, but the underlying issue causing the low voltage must be resolved to prevent the code from returning.
9. How much does it cost to repair the P0691 code on a 2014 GMC Sierra?
Repair costs vary depending on the cause, ranging from $50 for a new relay to $500 or more if the cooling fan motor or PCM needs replacement.
10. Can a bad PCM cause the P0691 code in a 2014 GMC Sierra?
While less common, a malfunctioning PCM can cause the P0691 code if it fails to properly control the cooling fan circuit.
Discuss the causes and fixes for P0691 2014 GMC Sierra OBDII Code
Code P0691 2014 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.