Engine-Codes - Chevrolet - P1641 CHEVROLET

P1641 CHEVROLET - Cooling Fan Relay 1 Control Circuit

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P1641 CHEVROLET Possible Causes

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

How is the P1641 CHEVROLET code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the P1641 CHEVROLET code

Labor: 1.0

The cost to diagnose the P1641 CHEVROLET code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Cooling Fan not working

P1641 CHEVROLET Meaning

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.

More Information

Need more information on how to fix the P1641 CHEVROLET code?
Get Access to Factory Service Manuals

Need more help?

Get the P1641 Chevrolet code diagnosed by a professional: Find a repair shop in your area