AutoCodes – Pontiac – P0691 Pontiac

P0691 Pontiac Code - Cooling Fan 1 Control Circuit Low

Quick Answer

The engine cooling fan system is composed of electric cooling fan and a cooling fan control module. Common causes include Faulty Cooling Fan 1 Relay, Cooling Fan 1 Relay harness is open or shorted, Cooling Fan 1 Relay 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: P0691 Pontiac indicates Cooling Fan 1 Control Circuit Low.
Common causes: Common causes include Faulty Cooling Fan 1 Relay, Cooling Fan 1 Relay harness is open or shorted, Cooling Fan 1 Relay 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 1,368

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 Jul 19, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0691 Pontiac Description

The engine cooling fan system is composed of electric cooling fan and a cooling fan control module. The Engine Control Module (ECM) controls the fan speed by sending a Pulse Width Modulated (PWM) signal to the cooling fan control module. The cooling fan control module varies the voltage drop across the cooling fan motor in relation to the pulse width modulated signal, allowing the cooling fan to operate at variable speeds. The cooling fan speed is affected by many different operating conditions and the ECM will adjust the duty cycle based on cooling system requirements.
Generally, the ECM will operate the cooling fan at specific percentages but, may scale the percentages either higher or lower in response to generator demand. The percentages at which the cooling fan operates may vary between vehicle lines and engines.
The cooling fan control module is thermally protected to prevent module damage in the case of a short circuit condition in the cooling fan motor. The scan tool output control is only capable of operating the cooling fan in the speed percentages allowed by the ECM. When multiple cooling fan speed requests are received, the ECM operates the fan at the highest of the speed requests.
The Diagnostic Trouble Code (DTC) will be set when the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

**Cooling Fan design may vary

OBDII Code P0691 Pontiac - Cooling Fan 1 Control Circuit Low - AutoCodes.com — P0691 Pontiac Code - Cooling Fan 1 Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC P0691 Pontiac?

Faulty Cooling Fan 1 Relay
Cooling Fan 1 Relay harness is open or shorted
Cooling Fan 1 Relay circuit poor electrical connection
Faulty Cooling Fan 1
Faulty Cooling Fan Control Module
Faulty Engine Control Module (ECM)

How to Fix the DTC P0691 Pontiac?

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 P0691 Pontiac 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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Need Help with the Code?

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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 P0691 Pontiac Code

1. What are the common symptoms of OBDII code P0691 in a Pontiac related to Cooling Fan 1 Control Circuit Low?

- Common symptoms include overheating of the engine, the cooling fan not engaging, and the Check Engine light being illuminated.

2. What can cause the OBDII code P0691 on a Pontiac indicating Cooling Fan 1 Control Circuit Low?

- Possible causes can include a faulty cooling fan control module, damaged wiring or connectors in the cooling fan circuit, or a malfunctioning engine coolant temperature sensor.

3. How can I diagnose the issue related to OBDII code P0691 in my Pontiac's Cooling Fan 1 Control Circuit Low?

- You can use a multimeter to test the cooling fan control module, inspect the wiring and connectors for any signs of damage, and check the engine coolant temperature sensor for proper functioning.

4. Can driving the vehicle with OBDII code P0691 Pontiac Cooling Fan 1 Control Circuit Low cause further damage?

- Driving with this code can lead to engine overheating and potential damage, so it is recommended to address the issue promptly to prevent any serious complications.

5. What are some repair tips for resolving OBDII code P0691 in a Pontiac related to Cooling Fan 1 Control Circuit Low?

- Repair tips may include replacing the cooling fan control module, repairing any damaged wiring or connectors, and ensuring the engine coolant temperature sensor is functioning correctly.

6. Is it safe to continue driving my Pontiac with the Cooling Fan 1 Control Circuit Low issue if the cooling fan is still operational?

- It is not recommended to drive the vehicle with this issue as the cooling fan may not be functioning optimally, potentially leading to engine overheating and damage.

7. Will resetting the OBDII code P0691 in my Pontiac temporarily fix the Cooling Fan 1 Control Circuit Low problem?

- Resetting the code may temporarily turn off the Check Engine light, but it will not resolve the underlying issue causing the Cooling Fan 1 Control Circuit Low problem.

8. Can a DIY enthusiast fix the OBDII code P0691 Pontiac Cooling Fan 1 Control Circuit Low issue?

- Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the issue, but it is recommended to consult a professional for complex electrical problems.

9. Are there any recalls or technical service bulletins related to the OBDII code P0691 Pontiac Cooling Fan 1 Control Circuit Low?

- It is advisable to check with Pontiac dealerships or online resources for any recalls or technical service bulletins related to this specific OBDII code to see if there are known issues or solutions provided by the manufacturer.

10. How much can I expect to pay for repairs related to OBDII code P0691 Pontiac Cooling Fan 1 Control Circuit Low?

- Repair costs can vary depending on the specific issue causing the code, but it is recommended to obtain quotes from reputable mechanics or dealerships for an accurate estimate.