TSBs

Fixing Volkswagen Cooling Fans

Sept. 19, 2022

This bulletin applies to all Volkswagen 2004 and newer vehicles with electronically controlled cooling fans.

This bulletin applies to all Volkswagen 2004 and newer vehicles with electronically controlled cooling fans. The pin-out for an electronically controlled cooling fan is as follows:

1. Terminal 30 battery power

2. Key ON power

3. Pulse with modulated (PWM) control signal from ECM

4. Ground

Duty cycle of PWM control signal from the ECM determines fan speed. For example, key on is 25%, low fan speed is 50% and high speed is 75%. When the fan control module has key on power, it must receive a PWM control signal from the ECM. If the control signal is not present with key on power, fans will run constantly. Early vehicles such as the Tourag, Phaeton and W8 Passat will run the cooling fans at all times when a cooling system fault is present in the PCM.

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

About the Author

Mike Mavrigian | Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.