AutoCodes – Chevrolet – P1641 Chevrolet

P1641 Chevrolet Code - Cooling Fan Relay 1 Control Circuit

Quick Answer

Ignition voltage is supplied to the Cooling Fan relay coil. Common causes include Faulty Cooling Fan Relay, Cooling Fan Relay harness is open or shorted, Cooling Fan Relay circuit poor electrical component. 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: P1641 Chevrolet indicates Cooling Fan Relay 1 Control Circuit.
Common causes: Common causes include Faulty Cooling Fan Relay, Cooling Fan Relay harness is open or shorted, Cooling Fan Relay circuit poor electrical component.
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 20,489

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 Sep 04, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1641 Chevrolet Description

Ignition voltage is supplied to the Cooling Fan relay coil. The Powertrain Control Module (PCM) controls the relay by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status will change causing the code to set.
The relay is used to control the high current flow to the cooling fan motors. This allows the PCM driver to only have to handle the relatively low current used by the relay.

OBDII Code P1641 Chevrolet - Cooling Fan Relay 1 Control Circuit - AutoCodes.com — P1641 Chevrolet Code - Cooling Fan Relay 1 Control Circuit

What does this mean?

What are the Possible Causes of the DTC P1641 Chevrolet?

Faulty Cooling Fan Relay
Cooling Fan Relay harness is open or shorted
Cooling Fan Relay circuit poor electrical component

How to Fix the DTC P1641 Chevrolet?

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 P1641 Chevrolet 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 P1641 Chevrolet Code

1. What are the common symptoms of OBDII code P1641 in a Chevrolet related to the Cooling Fan Relay 1 Control Circuit?

- Common symptoms include the cooling fan not turning on or running continuously, engine overheating, and a warning light illuminated on the dashboard.

2. What are some possible causes of OBDII code P1641 in a Chevrolet indicating issues with the Cooling Fan Relay 1 Control Circuit?

- Possible causes may include a faulty cooling fan relay, damaged wiring or connectors in the cooling fan circuit, a malfunctioning engine coolant temperature sensor, or a problem with the cooling fan itself.

3. How can I diagnose the OBDII code P1641 in my Chevrolet related to the Cooling Fan Relay 1 Control Circuit?

- Diagnosing this code typically involves using a scan tool to check for related trouble codes, testing the cooling fan relay, inspecting the wiring and connectors for damage, and verifying the operation of the cooling fan.

4. What are the repair options for resolving OBDII code P1641 in a Chevrolet associated with the Cooling Fan Relay 1 Control Circuit?

- Repair options may involve replacing the cooling fan relay, repairing any damaged wiring or connectors, testing and replacing the engine coolant temperature sensor if needed, or replacing the cooling fan itself if it is found to be faulty.

5. Are there any tips for preventing OBDII code P1641 from recurring in a Chevrolet with issues in the Cooling Fan Relay 1 Control Circuit?

- Regularly inspecting the cooling fan system for any signs of wear or damage, ensuring proper maintenance of the cooling system, and addressing any overheating issues promptly can help prevent the recurrence of this code.

6. Can driving with OBDII code P1641 in a Chevrolet related to the Cooling Fan Relay 1 Control Circuit cause further damage to the vehicle?

- Driving with this code may lead to engine overheating, which can cause serious damage to engine components. It is recommended to address the issue promptly to prevent potential damage.

7. Is it safe to continue driving my Chevrolet with OBDII code P1641 indicating problems with the Cooling Fan Relay 1 Control Circuit?

- It is not recommended to drive the vehicle with this code present, as it can lead to engine overheating and potential damage. It is best to address the issue as soon as possible.

8. How much does it typically cost to repair OBDII code P1641 in a Chevrolet related to the Cooling Fan Relay 1 Control Circuit?

- The cost of repair can vary depending on the exact cause of the issue and the labor rates in your area. Replacing the cooling fan relay or sensor may cost a few hundred dollars, while more extensive repairs could cost more.

9. Can I reset OBDII code P1641 in my Chevrolet related to the Cooling Fan Relay 1 Control Circuit without fixing the underlying issue?

- While you can clear the code using a scan tool, it is not recommended to do so without addressing the root cause. Resetting the code without fixing the problem will likely result in it reappearing once the issue persists.

10. How long does it usually take to repair OBDII code P1641 in a Chevrolet indicating issues with the Cooling Fan Relay 1 Control Circuit?

- The repair time can vary depending on the exact cause of the problem and the extent of the repairs needed. Simple fixes like replacing a relay can be done in a relatively short time, while more complex issues may take longer to diagnose and repair.