AfterMarketNews Auto Care Pro AutoProJobs Auto-Video.com Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service

Respect The Tech: When Art Does Not Reflect Real Life

We are an industry very focused on our own image. But, sometimes we need to step back to get a global perspective on the issue. Shutterstock.com is a website where photographers can sell stock photographs online for magazines, advertisements and billboards....

Read more...

Consistently Selling Maintenance Boosts Customer Satisfaction, ­Retention

While seasons change, your maintenance strategy should be consistent year-round. For this edition of ­Maintenance Chronicle, we take a snapshot of the maintenance sales of an 11-bay shop in ­upstate New York during a two-week ­period. What did...

Read more...

Documenting Inspections: Are You Leaving Maintenance Dollars On The Table?

How do you translate scribbles on a ­repair order into sales? There is no magic trick involved — the key is to document the vehicle ­inspection process. The more you know about your customers’ vehicles, and the more you are able to document...

Read more...

Audi: Transmission Does Not Shift Due To Cabin Air Filter

Model: 2001 Audi A6 Avant Quattro, 2.8L Complaint The customer states the transmission does not shift. Cause Confirmed the customer’s complaint and found the transmission did not shift. Inspected the automatic transmission fluid level and condition...

Read more...

Kia Driveability Diagnostics: Chasing Intermittent Gremlins

This month, we find ourselves looking at a 2004 Kia ­Sorrento that the owner says is losing power and stalling with no established pattern. It will run well for days or even weeks at a time without a problem, only to then act up without warning,...

Read more...

Mercedes-Benz: Noise in Front of Vehicle/Dash Area

Affected Models: Model 203.052/054/092/056/087 Model 209.356/365/372/375/376/377/456/ 465/472/475/476/477 If you receive customer reports of noise from the center of the dash area in the above-listed vehicles, this may be caused by a portion of...

Read more...

Ford: Low-Speed Strut Noise

MODELS: • 2006-2009 Fusion • 2007 Zephyr • 2007-2009 MKZ • 2006-2009 Milan Some vehicles built before 8/5/2008 may exhibit a popping, rubbing, grunting, squeaking, crunching or creaking type noise from the front strut mount when going over...

Read more...

Honda Civic Alignment Spec: 2006-'11

Built on a high-rigidity unit-body platform, the 2006-2011 Civic has a MacPherson strut front ­suspension and a multi-link rear suspension. The eighth generation switched from a high mounted to a low mounted steering rack and significantly increased...

Read more...

False ABS, ESC Activation Causes and Cures

The first mass-produced anti-lock braking systems (ABS) were introduced in 1985. By 2008, almost every passenger vehicle came standard with ABS. Next, electronic stability control (ESC) became a mandated safety feature for the 2012 model year. Along with...

Read more...

Equipment and Tool Institute Launches an Important Market Research Study on New Car Buying Preferences of Consumers

In an effort to assist its members in having the latest market information and bringing new and improved equipment and tools to the marketplace, The Equipment and Tool Institute (ETI) has launched a series of Market Research Projects. The current...

Read more...

Redline Detection Names 2015 Redline Rock Star Performance Award Winner

Redline Detection has announced the winner of its 2015 Redline Rock Star Performance Award. Rob McNees of Truck Centers, Inc. (TCI) was selected by the Redline Technical Advisory Board as the winner and received more than $4,000 in cash and prizes from...

Read more...

Rivet Bonding Comes Full Blast

By Mitch Becker for BodyShop Business   By now, most of you have heard the news that Ford has mainstreamed rivet bonding with the introduction of the 2015 F-150. This has forced many shops to look into some new equipment, such as self piercing...

Read more...

Home Climate Control Tech Tip: Volkswagen Has No Power to the A/C Compressor Clutch

Print Print Email Email

Vehicle Application: 2000 Beetle 2.0, 2002 Beetle 1.9, 2002 Golf 1.8, 1999-2003 Golf 2.0, 2000-’05 Jetta 1.8, 1.0, 1999-2005 Jetta 2.0 and 2000-’02 Jetta 2.8

Customer Concern: The A/C is not working. There is no power to the A/C compressor clutch and it does not engage. (Manual climate control.)

Potential Causes: A/C Compressor, A/C Pressure Sensor F129, A/C Switch, Ambient Temperature Switch F38, Battery Auxiliary Fuse Box, Fan Control Module J293 (and Wiring), Fuse or Lost Throttle Basic Settings

Tests/Procedures:

Test the Fan Control (FCM) module inputs as follows:

1. All tests are performed with the ignition key and A/C switched on and the connectors connected to the fan module. The fan control module is located under the radiator and has two connectors: a 14-pin (T14) and a 4-pin (T4).

2. Check for 12 volts to pin T4a/1 (red/black) and T4a/3 (red) via fuses S164 and S180 respectively, in the fuse box on top of the battery, at all times. (Note: It’s critical to check these power sources in a loaded condition as damage to the battery auxiliary fuse box can cause a loss of voltage under load. Visually inspect the condition of the three push-in type fuses for corrosion and burn marks.)

3. Verify an approximate 70% duty cycle from the A/C pressure sensor at pin T14/2 (white) with the ignition on and the compressor not running (duty cycle will decrease as the high-side pressure increases). A duty cycle above 80 or below 10 will command the compressor off and would indicate a faulty pressure sensor, if the compressor is not running and the refrigerant levels are normal.

4. Verify 12 volts to pin T14/4 (red/gray) via fuse 16, at all times.

5. Verify good ground to pin T14/6 (brown/black).

6. When the A/C is switched on and the blower motor is running at any speed, verify that 12 volts from the A/C switch in the instrument panel is available to pin T14/8 (blue/red). Note: The cooling fans should run at low speed whenever the A/C is switched on.

7. Verify 12 volts to pin T14/9 (black/blue) from fuse #5, when the ignition is in the “on” position.

8. Verify the presence of an 11-volt reference (actual voltage reading will oscillate between 7, 9 and 11 volts) at pin T14/13 (purple/yellow). The instrument cluster will ground this reference to request a compressor shutdown for an overheat condition. The cooling fans will also be running on high speed.

9. Disconnect the 14-pin connector. Using a fused 12-volt jumper, apply power to pin T14/10 (green/black). The compressor clutch should engage. If the compressor does not engage, check for a wiring harness open circuit or loss of ground at the compressor. Reconnect the 14-pin connector.

10. Disconnect the 14-pin connector and verify continuity between pin T14/14 (green/blue) and T14/5 (blue/red). This checks the Ambient Temperature Switch (ATS) (normal open circuit below 32° F, continuity above 32° F).

11. Verify the presence of an 11-volt reference voltage at pin T14/3 (green). The engine control module (ECM) will ground this reference to request a compressor shutdown for a wide open throttle (WOT) condition or lack of throttle basic setting. Eleven volts is the normal expected reading at this pin.

12. If all tests pass, the FCM is faulty and must be replaced.

Tech Tips:

Note: Pin T14/3 will be grounded by the ECM if the throttle basic settings are lost. Raising the engine rpm over 2,500 will cause the ECM to allow A/C operation if this is the case. If a ground condition exists on pin 3, perform a throttle basic setting procedure and recheck for correct voltage.

If needed, a repair kit is available from Volkswagen to replace the 14-pin fan control module connector, P/N 6X09737717 KIT.

Courtesy of Identifix.

The following two tabs change content below.
Underhood Service Staff Writers

Underhood Service Staff Writers

Underhood Service Staff Writers

Latest posts by Underhood Service Staff Writers (see all)

Latest articles from our other sites:

Audi: Transmission Does Not Shift Due To Cabin Air Filter

Model: 2001 Audi A6 Avant Quattro, 2.8L Complaint The customer states the transmission does not shift. Cause Confirmed the customer’s complaint and found the transmission did not shift. Inspected...More

Bosch Charitable Donation To Benefit Brad Keselowski's Checkered Flag Foundation

In recognition of Brad Keselowski’s exciting win at Sunday’s Auto Club 400 in Fontana, CA, Bosch Aftermarket NA is contributing $1,000 to the Team Penske driver’s Checkered Flag Foundation. Based...More

Audi: Transmission Does Not Shift Due To Cabin Air Filter

Model: 2001 Audi A6 Avant Quattro, 2.8L Complaint The customer states the transmission does not shift. Cause Confirmed the customer’s complaint and found the transmission did not shift. Inspected...More

Kia Driveability Diagnostics: Chasing Intermittent Gremlins

This month, we find ourselves looking at a 2004 Kia ­Sorrento that the owner says is losing power and stalling with no established pattern. It will run well for days or even weeks at a time without...More

Ford: Low-Speed Strut Noise

MODELS: • 2006-2009 Fusion • 2007 Zephyr • 2007-2009 MKZ • 2006-2009 Milan Some vehicles built before 8/5/2008 may exhibit a popping, rubbing, grunting, squeaking, crunching or creaking...More

Honda Civic Alignment Spec: 2006-'11

Built on a high-rigidity unit-body platform, the 2006-2011 Civic has a MacPherson strut front ­suspension and a multi-link rear suspension. The eighth generation switched from a high mounted to a low...More

Equipment and Tool Institute Launches an Important Market Research Study on New Car Buying Preferences of Consumers

In an effort to assist its members in having the latest market information and bringing new and improved equipment and tools to the marketplace, The Equipment and Tool Institute (ETI) has launched a...More

Redline Detection Names 2015 Redline Rock Star Performance Award Winner

Redline Detection has announced the winner of its 2015 Redline Rock Star Performance Award. Rob McNees of Truck Centers, Inc. (TCI) was selected by the Redline Technical Advisory Board as the winner and...More